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 fitness room was given a major upgrade and is now open 24/7. —Condé Nast, Condé Nast Traveler, 4 June 2026

The options at Miraval Berkshires abound, with hundreds of seasonal and year-round possibilities that guests can choose to align with their own intentional journey, whether that is mental well-being, relaxation and fitness, or reconnection with friends and family. —Robb Report Studio, Robb Report, 3 June 2026

The 135,735-square-foot hotel would have a full-service Chop Steakhouse and Bar Restaurant, meeting space, a fitness center and an outdoor pool. —Fousia Abdullahi, Fort Worth Star-Telegram, 3 June 2026

In 2022, the Defense Department relaxed standards for weight and fitness. —Paula Chesley, STAT, 3 June 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