/air roh"biks/ , n.
1. Also called aerobic exercises . ( used with a pl. v. ) any of various sustained exercises, as jogging, rowing, swimming, or cycling, that stimulate and strengthen the heart and lungs, thereby improving the body's utilization of oxygen.
2. ( used with a sing. v. ) a physical fitness program based on such exercises: Aerobics is a good way to get your body in shape.
[ 1965-70; see AEROBIC, -ICS; prob. shortened from aerobic exercises on the model of CALISTHENICS ]