(1) (That's why we all love the New Yorker's fanatical devotion to the diaeresis.)
Dieresis
Definition:
(n.) The separation or resolution of one syllable into two; -- the opposite of synaeresis.
(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.