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

Eight three-story and six four-story apartment buildings make up the community along with learning centers, a fitness studio, courtyards and community lounges, recreation and play areas and surface parking. —Darrell Smith, Sacbee.com, 14 Nov. 2025

Among action film fans, Grillo’s fitness regimen is the stuff of legend. —Patrick Brzeski, HollywoodReporter, 13 Nov. 2025

The founders envision hosting events, from fitness classes to creative workshops. —Ryma Chikhoune, Footwear News, 13 Nov. 2025

The fitness world can often be intimidating, but Savannah Polci has created a haven that stands out for its warmth and authenticity, that moves with purpose, and finds joy in the process. —William Jones, USA Today, 12 Nov. 2025

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