- aerobic exercise that stimulates and strengthens the heart and lungs: I mostly use weights, but I always add a little cardio into my routine.
- of or relating to aerobic exercise: The class begins with a slow and steady warmup, and then it switches to a cardio workout.
- of or relating to the heart; cardiovascular: He's a hugely successful cardio surgeon.
- a combining form meaning “heart,” used in the formation of compound words: cardiogram.
- heart
