prefix meaning “not,” from Latin a-, short for ab “away from” (e.g. avert), or its cognate, Greek a-, short for apo “away from, from,” both cognate with Sanskrit apa “away from,” Gothic af, Old English of (see apo-).
prefix meaning “not,” from Greek a-, an- “not,” from PIE root *ne “not” (see un-).
- Without; not:acellular.
- A prefix meaning without or not when forming an adjective (such as amorphous, without form, or atypical, not typical), and absence of when forming a noun (such as arrhythmia, absence of rhythm). Before a vowel or h it becomes an- (as in anhydrous, anoxia).