Definition - A process of language change where there is a gradual and unintentional loss of a short unaccented vowel at the beginning of a word.
Note: Someday it will be called phesis.

Example -
The word squire was derived from esquire and the word mend from amend by this process.

Etymology -
The term derives from the Greek aphienai, to send forth (from Greek apo, from + hienai, to send). It was coined by the primordial editor of the OED, James Murray .

Oxford English Dictionary -
Its first citation is from 1880 (Murray citing himself):
"The Editor can think of nothing better than to call the phenomenon Aphesis. .. and the resulting forms aphetic forms."
(J. A. H. Murray in Transactions of the Philological Society, 175)

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