1) Diacritic 2) Diacritical mark 3) Diaeresis 4) Mark missing from naive 5) Relative of an umlaut 6) Two dots placed over a vowel 7) Umlaut 8) Umlaut doppelganger 1) Diaeresis 2) Umlaut 
• (n.) A mark consisting of two dots [/], placed over the second of two adjacent vowels, to denote that they are to be pronounced as distinct letters; as, cooperate, aerial. • (n.) The separation or resolution of one syllable into two; -- the opposite of synaeresis. • (n.) Same as Diaeresis.
An alternative term for solution of continuity. ... Origin: G. Diairesis, a division ... (05 Mar 2000) ... 
(di-er´ә-sis) the division or separation of parts normally united. the surgical separation of parts.
(also called an umlaut) A diacritic mark (¨) to show that vowels represent sounds of different qu
Di·er'e·sis noun [ New Latin ] Same as Diæresis . 
Type: Term Pronunciation: dī-er′ĕ-sis Synonyms: solution of continuity
the separation of two adjacent vowels, dividing one syllable into two. · a sign (¨) placed over the second of two adjacent vowels to indicate separate pronunciation, as in one spelling of the older forms naïve and coöperate: no longer widely used in English. · the division made in a line or verse by coincidence of the end of a foot ...