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

The gym too is stylishly designed—with hemlock floors and forgiving lights—and the fitness equipment is up-to-date, if unfortunately not sourced from Olympus itself. —Condé Nast, Condé Nast Traveler, 7 Mar. 2026

The driveway was reconfigured to create a larger backyard, now home to a pool, guesthouse, fitness center, and patios. —Paige Reddinger, Robb Report, 7 Mar. 2026

Aspirational fitness lore and new sounds (for Styles) notwithstanding, Disco feels deliberately designed to make sure that his six months of Together, Together residencies this year feel light and bouncy. —Craig Jenkins, Vulture, 6 Mar. 2026

Fred Sassani, founder of Bodies By Design, is a certified personal trainer and nutrition specialist with over 20 years of experience helping individuals achieve their health and fitness goals. —Fred Sassani, Austin American Statesman, 6 Mar. 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