fitness

noun

fit·​ness ˈfit-nəs 

1

: the quality or state of being fit

2

: the capacity of an organism to survive and transmit its genotype to reproductive offspring as compared to competing organisms

also : the contribution of an allele or genotype to the gene pool of subsequent generations as compared to that of other alleles or genotypes

Synonyms

• health
• healthiness
• heartiness
• robustness
• sap
• soundness
• verdure
• wellness
• wholeness
• wholesomeness

Examples of fitness in a Sentence

a gymnastics program promoting fitness and agility in school-aged children

I have to question the fitness of wearing a bright red dress to a funeral.

Recent Examples on the Web

Police and fire departments have sometimes defeated disparate impact challenges over physical fitness test requirements on grounds that good fitness is essential to those jobs. —Michael McCann, Sportico.com, 5 May 2025

Here’s what fitness experts say about using the activity as a training tool. —Alyssa Ages, New York Times, 3 May 2025

As a former fitness coach who now works remotely, his wardrobe is basically a rotation of joggers, performance tees, and hoodies that can handle everything from video calls to weekend hikes and gym sessions. —Kayla Kitts, Travel + Leisure, 3 May 2025

On Friday, the brand — best known for its internet-breaking Bala Bangles, $55 — is launching Bala Mama, a collection of fitness equipment for pre- and postnatal. —Emily Burns, Footwear News, 2 May 2025

Word History

First Known Use

1580, in the meaning defined at sense 1

Phrases Containing fitness

• physical fitness

Rhymes for fitness

• witness
• eyewitness
• unfitness

Medical Definition

fitness

noun

fit·​ness ˈfit-nəs 

: the capacity of an organism to survive and transmit its genotype to reproductively fertile offspring as compared to competing organisms

also : the contribution of an allele or genotype to the gene pool of subsequent generations as compared to that of other alleles or genotypes