Definition of A-
A-: Prefix indicating the absence or depletion of something: for example, aphagia (not eating) or aphonia (voiceless). The related prefix an- is usually used before a vowel, as in anemia (without blood) and anoxia (without oxygen).
Last Editorial Review: 3/19/2012
Back to MedTerms online medical dictionary A-Z List
Need help identifying pills and medications?
Get the latest health and medical information delivered direct to your inbox FREE!