Wordnet 3.0
NOUN (1)
1.
the gradual disappearance of an initial (usually unstressed) vowel or syllable as in `squire' for `esquire';
The Collaborative International Dictionary of English v.0.48:
Aphesis \Aph"e*sis\, n. [Gr. ? a letting go; ? + ? to let go.]
The loss of a short unaccented vowel at the beginning of a
word; -- the result of a phonetic process; as, squire for
esquire. --New Eng. Dict.
[1913 Webster]
WordNet (r) 3.0 (2006):
aphesis
n 1: the gradual disappearance of an initial (usually
unstressed) vowel or syllable as in `squire' for `esquire'