[ kahr-dee-oh ]

  1. aerobic exercise that stimulates and strengthens the heart and lungs: I mostly use weights, but I always add a little cardio into my routine.

  1. of or relating to aerobic exercise: The class begins with a slow and steady warmup, and then it switches to a cardio workout.

  2. of or relating to the heart; cardiovascular: He's a hugely successful cardio surgeon.

Origin of cardio

First recorded in 1960–65

Words Nearby cardio

Other definitions for cardio- (2 of 2)


  1. a combining form meaning “heart,” used in the formation of compound words: cardiogram.

Origin of cardio-

<Greek kardio-, combining form of kardía
  • Also especially before a vowel, cardi-. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use cardio in a sentence

British Dictionary definitions for cardio-


combining form
  1. heart: cardiogram

Origin of cardio-

from Greek kardia heart

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012