A-G ratio (albumin/globulin ratio)

A-R (apical radial (pulse))

A-T (baby teeth)

A-VO2 (arteriovenous oxygen)

a.c. (before meal (L. ante cibum))

a.m. (morning, before noon (ante meridiem))

a.p. (before meal (ante prandium))

a.p. (antepartum)

a.p. (anterior-posterior)

A/C (assist/control)