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 of fitness

• health
• wellness
• strength

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

This force potentially impacts fitness and survival, according to the team. — Laura Baisas, Popular Science, 16 July 2026

For a slower pace, add in ceramics, art, and cooking classes, relax pool or lakeside, take one of the many wellness or fitness classes, or try paddle board yoga. — Cameron Beall, Southern Living, 16 July 2026

Nearby, the historic Sporting Club houses an indoor pool, sauna, water circuit, and fitness center. — Condé Nast, Condé Nast Traveler, 15 July 2026

So is Mosquera, though a lack of fitness will likely mean minimal to no involvement on matchday for him. — Daniel Sperry, Kansas City Star, 15 July 2026

Word History

First Known Use

1574, 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