'aphaeresis' originates from Greek, specifically the word 'aphaíresis' (ἀφαίρεσις), where 'a-' meant 'away' (a privative) and 'phaírein' meant 'to take'.

'aphaeresis' passed into Latin and Medieval/Modern scholarly usage from the Greek 'aphaíresis', and the term entered English in forms such as 'aphæresis' and 'aphaeresis' in learned contexts.

Initially it meant 'a taking away' in a general sense; over time it specialized to the linguistic/rhetorical sense 'removal of an initial sound or syllable'.