aphesis

In the Bible, forgiveness (aphesis) has a special importance and it means release, liberation from sin, guilt or debt.

(17.) The Greek word aphesis means liberation (concretely) in Is.

The loss of that first a from alackaday results from a process known as aphesis. It is a gradual development that causes the dropping of an unaccented vowel at the beginning of a word.

But whereas Old English had only the form (-)iewan, Old Saxon had two forms, ogian and togian, the latter form the reflex, with aphesis, of *at-ogian.(9) Thus Old Saxon could, whereas Old English could not, provide an equivalent to Old English (-)iewan which, when the noun tekan and the verb fell in the same line, permitted noun and verb to alliterate on t-.

One of the elements of grammaticalization, the aphesis, constitutes a proof for the phonetic reduction in progress.