Obtruncation noun [ Latin obtruncatio .] The act of lopping or cutting off. [ R.] Cockeram.

Obtrusion noun [ Latin obtrusio . See Obtrude .]
1. The act of obtruding; a thrusting upon others by force or unsolicited; as, the obtrusion of crude opinions on the world.

2. That which is obtruded. Milton.

Obtrusionist noun One who practices or excuses obtrusion. [ R.] Gent. Mag.

Obtrusive adjective Disposed to obtrude; inclined to intrude or thrust one's self or one's opinions upon others, or to enter uninvited; forward; pushing; intrusive. -- Ob*tru"sive*ly , adverb - - Ob*tru"sive*ness , noun

Not obvious, not obtrusive , but retired.

Milton.

Obtund transitive verb [ imperfect & past participle Obtunded ; present participle & verbal noun Obtunding .] [ Latin obtundere , obtusum ; ob (see Ob- ) + tundere to strike or beat. See Stutter .] To reduce the edge, pungency, or violent action of; to dull; to blunt; to deaden; to quell; as, to obtund the acrimony of the gall. [ Archaic] Harvey.

They . . . have filled all our law books with the obtunding story of their suits and trials.

Milton.

Obtundent noun [ Latin obtundens , present participle of obtundere .] (Medicine) A substance which sheathes a part, or blunts irritation, usually some bland, oily, or mucilaginous matter; -- nearly the same as demulcent . Forsyth.

Obtunder noun (Medicine) That which obtunds or blunts; especially, that which blunts sensibility.

Obturate transitive verb [ imperfect & past participle Obturated ; present participle & verbal noun Obturating .] [ Latin obturatus ; p.p. of obturare .] To stop or close, as an opening; specif., (Ordnance) , to stop (a gun breech) so as to prevent the escape of gas in firing.

Obturation noun [ Latin obturare to stop up: confer French obturation .] The act of stopping up, or closing, an opening. "Deaf by an outward obturation ." Bp. Hall.

Obturator noun [ New Latin , from Latin obturare to stop up: confer French obturateur .]
1. That which closes or stops an opening.

2. (Surg.) An apparatus designed to close an unnatural opening, as a fissure of the palate.

Obturator adjective (Anat.) Serving as an obturator; closing an opening; pertaining to, or in the region of, the obturator foramen; as, the obturator nerve.

Obturator foramen (Anat.) , an opening situated between the public and ischial parts of the innominate bone and closed by the obturator membrane ; the thyroid foramen.

Obturator noun
1. (Ordnance) Any device for preventing the escape of gas through the breech mechanism of a breech-loading gun; a gas check.

2. (Photog.) A camera shutter.

Obtusangular adjective See Obstuseangular .

Obtuse adjective [ Compar. Obtuser ; superl. Obtusest .] [ Latin obtusus , past participle of obtundere to blunt: confer French obtus . See Obtund .]
1. Not pointed or acute; blunt; -- applied esp. to angles greater than a right angle, or containing more than ninety degrees.

2. Not having acute sensibility or perceptions; dull; stupid; as, obtuse senses. Milton.

3. Dull; deadened; as, obtuse sound. Johnson.

Obtuse-angled, obtuse-angular adjective Having an obtuse angle; as, an obtuse- angled triangle.

Obtusely adverb In an obtuse manner.

Obtuseness noun State or quality of being obtuse.

Obtusion noun [ Latin obtusio , from obtundere to blunt. See Obtund .]
1. The act or process of making obtuse or blunt.

2. The state of being dulled or blunted; as, the obtusion of the senses. Harvey.

Obtusity noun Obtuseness. Lond. Quart. Rev.

Obumbrant adjective [ Latin obumbrans , present participle] (Zoology) Overhanging; as, obumbrant feathers.

Obumbrate transitive verb [ Latin obumbratus , past participle of obumbrare to overshadow, cloud; ob + umbrare to shade.] To shade; to darken; to cloud. [ R.] Howell.

Obumbration noun [ Latin obumbratio .] Act of darkening or obscuring. [ R.] Sir T. More.

Obuncous adjective [ Latin obuncus ; ob (see Ob- ) + uncus hooked.] Hooked or crooked in an extreme degree. Maunder.

Obvention noun [ Latin obvention , from obvenire to come before or in the way of, to befall; ob (see Ob- ) + venire to come: confer French obvention .] The act of happening incidentally; that which happens casually; an incidental advantage; an occasional offering. [ Obsolete] "Tithes and other obventions ." Spenser.

Legacies bequeathed by the deaths of princes and great persons, and other casualities and obventions .

Fuller.

Obversant adjective [ Latin obversans , present participle of obversari to hover before; ob (see Ob- ) + versare to move about.] Conversant; familiar. [ Obsolete] Bacon.

Obverse adjective [ Latin obversus , past participle of obvertere . See Obvert .] Having the base, or end next the attachment, narrower than the top, as a leaf.

Obverse noun [ Confer F. obverse , obvers . See Obverse , adjective ]
1. The face of a coin which has the principal image or inscription upon it; -- the other side being the reverse .

2. Anything necessarily involved in, or answering to, another; the more apparent or conspicuous of two possible sides, or of two corresponding things.

The fact that it [ a belief] invariably exists being the obverse of the fact that there is no alternative belief.

H. Spencer.

Obversely adverb In an obverse manner.

Obversion noun [ Latin obversio a turning towards.]
1. The act of turning toward or downward.

2. (Logic) The act of immediate inference, by which we deny the opposite of anything which has been affirmed; as, all men are mortal; then, by obversion , no men are immortal. This is also described as "immediate inference by privative conception." Bain.

Obvert transitive verb [ imperfect & past participle Obverted ; present participle & verbal noun Obverting .] [ Latin obvertere ; ob (see Ob- ) + vertere to turn. See Verse .] To turn toward.

If its base be obverted towards us.

I. Watts.

Obviate transitive verb [ imperfect & past participle Obviated ; present participle & verbal noun Obviating .] [ Latin obviare ; ob (see Ob- ) + viare to go, from via way. See Voyage .]

1. To meet in the way. [ Obsolete]

Not to stir a step to obviate any of a different religion.

Fuller.

2. To anticipate; to prevent by interception; to remove from the way or path; to make unnecessary; as, to obviate the necessity of going.

To lay down everything in its full light, so as to obviate all exceptions.

Woodward.

Obviation noun The act of obviating, or the state of being obviated.

Obvious adjective [ Latin obvius ; ob (see Ob- ) + via way. See Voyage .]
1. Opposing; fronting. [ Obsolete]

To the evil turn
My obvious breast.

Milton.

2. Exposed; subject; open; liable. [ Obsolete] " Obvious to dispute." Milton.

3. Easily discovered, seen, or understood; readily perceived by the eye or the intellect; plain; evident; apparent; as, an obvious meaning; an obvious remark.

Apart and easy to be known they lie,
Amidst the heap, and obvious to the eye.

Pope.

Syn. -- Plain; clear; evident. See Manifest .

-- Ob"vi*ous*ly , adverb -- Ob"vi*ous- ness , noun

Obvolute, Obvoluted adjective [ Latin obvolutus , past participle of obvolvere to wrap round; ob (see Ob- ) + volvere to roll.] Overlapping; contorted; convolute; -- applied primarily, in botany, to two opposite leaves, each of which has one edge overlapping the nearest edge of the other, and secondarily to a circle of several leaves or petals which thus overlap.

Oby noun See Obi .

Oca noun [ Spanish ] (Botany) A Peruvian name for certain species of Oxalis ( O. crenata , and O. tuberosa ) which bear edible tubers.

Ocarina noun [ Confer Italian carino pretty.] (Mus.) A kind of small simple wind instrument.

Occamy noun [ A corruption of alchemy .] An alloy imitating gold or silver. [ Written also ochimy , ochymy , etc.]

Occasion (ŏk*kā"zhŭn) noun [ French occasion , Latin occasio , from occidere , occasum , to fall down; ob (see Ob- ) + cadere to fall. See Chance , and confer Occident .]
1. A falling out, happening, or coming to pass; hence, that which falls out or happens; occurrence; incident.

The unlooked-for incidents of family history, and its hidden excitements, and its arduous occasions .

I. Taylor.

2. A favorable opportunity; a convenient or timely chance; convenience.

Sin, taking occasion by the commandment, deceived me.

Rom. vii. 11.

I'll take the occasion which he gives to bring
Him to his death.

Waller.

3. An occurrence or condition of affairs which brings with it some unlooked-for event; that which incidentally brings to pass an event, without being its efficient cause or sufficient reason; accidental or incidental cause.

Her beauty was the occasion of the war.

Dryden.

4. Need; exigency; requirement; necessity; as, I have no occasion for firearms.

After we have served ourselves and our own occasions .

Jer. Taylor.

When my occasions took me into France.

Burke.

5. A reason or excuse; a motive; a persuasion.

Whose manner was, all passengers to stay,
And entertain with her occasions sly.

Spenser.

On occasion , in case of need; in necessity; as convenience requires; occasionally. "That we might have intelligence from him on occasion ," De Foe.

Syn. -- Need; incident; use. See Opportunity .

Occasion (ŏk*kā"zhŭn) transitive verb [ imperfect & past participle Occasioned (- zhŭnd); present participle & verbal noun Occasioning .] [ Confer F. occasionner .] To give occasion to; to cause; to produce; to induce; as, to occasion anxiety. South.

If we inquire what it is that occasions men to make several combinations of simple ideas into distinct modes.

Locke.

Occasionable adjective Capable of being occasioned or caused. Barrow.

Occasional adjective [ Confer F. occasionnel .]
1. Of or pertaining to an occasion or to occasions; occuring at times, but not constant, regular, or systematic; made or happening as opportunity requires or admits; casual; incidental; as, occasional remarks, or efforts.

The . . . occasional writing of the present times.

Bagehot.

2. Produced by accident; as, the occasional origin of a thing. [ Obsolete] Sir T. Browne.

Occasional cause (Metaph.), some circumstance preceding an effect which, without being the real cause, becomes the occasion of the action of the efficient cause; thus, the act of touching gunpowder with fire is the occasional , but not the efficient, cause of an explosion.

Occasionalism noun (Metaph.) The system of occasional causes; -- a name given to certain theories of the Cartesian school of philosophers, as to the intervention of the First Cause, by which they account for the apparent reciprocal action of the soul and the body.

Occasionality noun Quality or state of being occasional; occasional occurrence. [ R.]

Occasionally adverb In an occasional manner; on occasion; at times, as convenience requires or opportunity offers; not regularly. Stewart.

The one, Wolsey, directly his subject by birth; the other, his subject occasionally by his preferment.

Fuller.

Occasionate transitive verb To occasion. [ Obsolete]

The lowest may occasionate much ill.

Dr. H. More.

Occasioner noun One who, or that which, occasions, causes, or produces. Bp. Sanderson.

Occasive adjective [ Latin occasivus , from occasus a going down, setting of the heavenly bodies, from occidere to fall or down. See Occasion .] Of or pertaining to the setting sun; falling; descending; western.

Occecation noun [ Latin occaecatio , from occaecare to make blind; ob + caecare to blind, from caecus blind.] The act of making blind, or the state of being blind. [ R.] "This inward occecation ." Bp. Hall.

Occident noun [ French, from Latin occidens , occidentis , from occidents , present participle of occidere to fall or go down. See Occasion .] The part of the horizon where the sun last appears in the evening; that part of the earth towards the sunset; the west; -- opposed to orient . Specifically, in former times, Europe as opposed to Asia; now, also, the Western hemisphere. Chaucer.

I may wander from east to occident .

Shak.