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

The project would include a splash pad, waterpark and pool restoration as well as pickleball courts, running track upgrades, outdoor fitness stations, an inclusive playground, and safety fencing around the club’s playground. — Post-Tribune, Chicago Tribune, 1 Nov. 2026

The Ocean & Harvest Spa is certainly a can't-miss, with an indoor pool, gym and fitness classes, and of course, the spa itself, where massages, facials, and hair and nail services can be booked. — Condé Nast, Condé Nast Traveler, 30 Oct. 2026

Her campaign denies any involvement in the apparent Sullivan scheme, but the New York Times story and prior reporting could be used to call into question her fitness to serve. — David Sivak, The Washington Examiner, 30 Oct. 2026

Clinical studies have found that cardiovascular fitness can slow the rate of decline, Vossel said. — Iris Kwok, Los Angeles Times, 30 Oct. 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