Octillion noun [ Latin octo eight + -illion , as in English million : confer French octillion .] According to the French method of numeration (which method is followed also in the United States) the number expressed by a unit with twenty-seven ciphers annexed. According to the English method, the number expressed by a unit with forty-eight ciphers annexed. See Numeration .

Octo-, Octa- [ Latin octo eight, Greek ..., with a combining form .... Confer Eight .] A combining form meaning eight ; as in octo decimal, octo decimal, octo locular.

Octoate noun (Chemistry) A salt of an octoic acid; a caprylate.

October noun [ Latin , the eighth month of the primitive Roman year, which began in March, from octo eight: confer French Octobre . See Octave .]
1. The tenth month of the year, containing thirty-one days.

2. Ale or cider made in that month.

The country gentlemen had a posset or drink they called October .

Emerson.

Octocera noun plural [ New Latin ] Octocerata.

Octocerata noun plural [ New Latin , from Greek ... eight + ..., a horn.] (Zoology) A suborder of Cephalopoda including Octopus, Argonauta, and allied genera, having eight arms around the head; -- called also Octopoda .

Octochord noun (Mus.) See Octachord .

Octodecimo adjective [ Latin octodecim eighteen. See Octavo , Decimal , and -mo .] Having eighteen leaves to a sheet; as, an octodecimo form, book, leaf, size, etc.

Octodecimo noun ; plural Octodecimos A book composed of sheets each of which is folded into eighteen leaves; hence; indicating more or less definitely a size of book, whose sheets are so folded; -- usually written 18mo or 18°, and called eighteenmo .

Octodentate adjective [ Octo- + dentate .] Having eight teeth.

Octodont adjective [ Octo- + Greek ..., ....] (Zoology) Of or pertaining to the Octodontidæ , a family of rodents which includes the coypu, and many other South American species.

Octoedrical adjective See Octahedral . [ Obsolete] Sir T. Browne.

Octofid adjective [ Octo- + root of Latin findere to split: confer French octofide .] (Botany) Cleft or separated into eight segments, as a calyx.

Octogamy noun [ Octo- + Greek ... marriage.] A marrying eight times. [ R.] Chaucer.

Octogenarian noun A person eighty years, or more, of age.

Octogenary adjective [ Latin octogenarrus , from octogeni eighty each, octoginta eighty, from octo eight. See Eight , Eighty .] Of eighty years of age. "Being then octogenary ." Aubrey.

Octogild noun [ Octo- + Anglo-Saxon gild payment.] (Anglo-Saxon Law) A pecuniary compensation for an injury, of eight times the value of the thing.

Octogonal adjective See Octagonal . [ Obsolete]

Octogynia noun plural [ New Latin , from Greek ... eight + ... a woman, female.] (Botany) A Linnaean order of plants having eight pistils.

Octogynian, Octogynous adjective (Botany) Having eight pistils; octagynous.

Octoic adjective [ See Octo- .] (Chemistry) Pertaining to, derived from, or resembling, octane; -- used specifically, to designate any one of a group of acids, the most important of which is called caprylic acid .

Octolocular adjective [ Octo- + locular .] (Botany) Having eight cells for seeds.

Octonaphthene noun [ Octo- + naphthene .] (Chemistry) A colorless liquid hydrocarbon of the octylene series, occurring in Caucasian petroleum.

Octonary adjective [ Latin octonarius , from octoni eight each, from octo eight.] Of or pertaining to the number eight. Dr. H. More.

Octonocular adjective [ Latin octoni eight each + English ocular .] Having eight eyes. Derham.

Octopede noun [ Octo- + Latin pes , pedis , foot.] (Zoology) An animal having eight feet, as a spider.

Octopetalous adjective [ Octo- + petal .] (Botany) Having eight petals or flower leaves.

Octopod noun [ Greek ... eight- footed; ... eight + poy`s , podo`s , foot: confer French octopode .] (Zoology) One of the Octocerata.

Octopoda noun plural [ New Latin ] (Zoology) (a) Same as Octocerata . (b) Same as Arachnida .

Octopodia noun plural [ New Latin , from Greek ... eight + ... a little foot.] (Zoology) Same as Octocerata .

Octopus noun [ New Latin See Octopod .] (Zoology) A genus of eight-armed cephalopods, including numerous species, some of them of large size. See Devilfish ,

Octoradiated adjective [ Octo- + radiated .] Having eight rays.

Octoroon noun [ Latin octo eight + -roon , as in quadroon .] The offspring of a quadroon and a white person; a mestee.

Octospermous adjective [ Octo- + Cr. ... seed.] (Botany) Containing eight seeds.

Octostichous adjective [ Octo- + Greek ... a row.] (Botany) In eight vertical ranks, as leaves on a stem.

Octostyle adjective [ Octo- + Greek ... a pillar: confer French octostyle .] (Architecture) Having eight columns in the front; -- said of a temple or portico. The Parthenon is octostyle , but most large Greek temples are hexastele . See Hexastyle . -- noun An octostyle portico or temple.

Octosyllabic, Octosyllabical adjective [ Latin octosyllabus . See Octo- , and Syllable .] Consisting of or containing eight syllables.

Octosyllable adjective Octosyllabic.

Octosyllable noun A word of eight syllables.

Octoyl noun [ Octo ic + -yl .] (Chemistry) A hypothetical radical (C ₈ H ₁₅ O), regarded as the essential residue of octoic acid.

Octroi noun [ French]
1. A privilege granted by the sovereign authority, as the exclusive right of trade granted to a guild or society; a concession.

2. A tax levied in money or kind at the gate of a French city on articles brought within the walls.

[ Written also octroy .]

Octuor noun [ From Latin octo eight + -uor , as in Latin quatuor .] (Mus.) See Octet . [ R.]

Octuple adjective [ Latin octuplus ; confer Greek ...: confer French octuple .] Eightfold.

Octyl noun [ Oct ane + - yl .] (Chemistry) A hypothetical hydrocarbon radical regarded as an essential residue of octane, and as entering into its derivatives; as, octyl alcohol.

Octylene noun [ Oct ane + eth ylene .] (Chemistry) Any one of a series of metameric hydrocarbons (C ₈ H ₁₆ ) of the ethylene series. In general they are combustible, colorless liquids.

Octylic adjective (Chemistry) Pertaining to, derived from, or containing, octyl; as, octylic ether.

Ocular adjective [ Latin ocularis , ocularius , from oculus the eye: confer French oculaire . See Eye , and confer Antler , Inveigle .]
1. Depending on, or perceived by, the eye; received by actual sight; personally seeing or having seen; as, ocular proof. Shak.

Thomas was an ocular witness of Christ's death.

South.

2. (Anat.) Of or pertaining to the eye; optic.

Ocular noun (Opt.) The eyepiece of an optical instrument, as of a telescope or microscope.

Ocularly adverb By the eye, or by actual sight.

Oculary adjective Of or pertaining to the eye; ocular; optic; as, oculary medicines. Holland.