Do you know ghouls from goblins and ghosts?
in classical Greek, the contraction of two vowels or diphthongs at the end of one word and the beginning of an immediately following word, as kan for kai an or houmos for ho emos. Crasis is especially common in some lyric poetry and in Old Comedy. The term sometimes refers to word-internal contraction in Latin, as nil from nihil. The word is from the Greek krasis, literally, "mixing or blending."