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

Apple expanded its business and offered new services, becoming intertwined with fitness, payments and entertainment. —Queenie Wong, Los Angeles Times, 22 Apr. 2026

Alcaraz, who was sporting a brace on his wrist, opened up about his brilliant 2025 season, as well as his fitness hopes heading into the French Open next month, after being named Sportsman of the Year. —Amanda Davies, CNN Money, 21 Apr. 2026

Additional features include a 1,700-square-foot outdoor terrace, an on-site fitness center with showers and bike storage. —Jessica Alvarado Gamez, Denver Post, 21 Apr. 2026

The spa There's no spa on site, but a 1,700-square-foot fitness center and the option of having an in-room Peloton set up (the virtual exercise company's Hudson Yards headquarters is visible from the hotel gym itself) will be much appreciated by fitness gurus. —Condé Nast, Condé Nast Traveler, 21 Apr. 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