Proclitic

Used as a noun as well as an adjective, proclitic refers to any word which is so closely connected with the following word that it loses own independent accent or sound value, and so sounds merely like a prefix to the following word.

For example, the first word of the Hebrew Bible ("in the beginning") is b^ereshit, and is made up of two words; the preposition be ('in') and "reshit ('beginning' without the article). In reading the word, however, the preposition loses its accent (sound) almost completely; it is, therefore, said to be proclitic.