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

• 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 AirPods Pro 3 offer active noise cancellation, heart-rate sensing, fitness tracking, and even live translation. —Sydney Lake, Fortune, 9 Oct. 2025

Forty years later, Fonbuena is a sales manager for a fitness equipment company and a father of four. —Helen Harlan, Sacbee.com, 9 Oct. 2025

The concerns come after the now-79-year-old campaigned last year against rival President Joe Biden, highlighting concerns surrounding Biden’s age and fitness. —Chad De Guzman, Time, 9 Oct. 2025

Murphy said the developer expects to soon introduce furniture, provide occasional pop-up shops and offer programming such as outdoor fitness classes or movies. —Jennifer Van Grove, San Diego Union-Tribune, 9 Oct. 2025

Word History

First Known Use

1580, 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