\Cra"sis\ (kr?"s?s), n. [LL., temperament, fr. Gr. ????,
fr. ???? to mix.]
1. (Med.) A mixture of constituents, as of the blood;
   constitution; temperament.
2. (Gram.) A contraction of two vowels (as the final and
   initial vowels of united words) into one long vowel, or
   into a diphthong; syn[ae]resis; as, cogo for coago.