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

Best Vuori Shorts Deals Beyond cozy joggers and leggings, Vuori also makes a number of great shorts, for fitness or travel. —Kristine Thomason, Travel + Leisure, 25 Dec. 2025

Walking supports heart health, metabolic health, weight control, and long-term fitness. —Jakob Roze, Health, 25 Dec. 2025

The Brea Life Time will also feature a variety of fitness classes, even ones for kids and teens. —Terri Daxon, Oc Register, 25 Dec. 2025

Stewart is among the many critics of Tapper’s involvement, as the CNN host previously defended Biden’s fitness while criticizing concerns that the former president was faltering. —Asher Notheis, The Washington Examiner, 25 Dec. 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