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

There is a compact, guests-only fitness center stocked with modern equipment and Peloton bikes, and those who need to take calls between omakase courses can use the attached business lounge and boardroom. — Condé Nast, Condé Nast Traveler, 9 July 2026

Visibility from professional athletes, fitness influencers and wellness practitioners has normalized at-home cold plunges as part of daily recovery routines rather than a specialized therapy reserved for elite athletes. — Samantha Agate, Fort Worth Star-Telegram, 9 July 2026

The two methods share some equipment principles but pursue different fitness goals. — Hanna Wickes, Sacbee.com, 9 July 2026

The project was slated for a 2027 completion, and would also include ground-floor retail, a rooftop swimming pool and a fitness center, and 100,000 square feet of amenities. — Matthew Sedacca, Curbed, 8 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