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
• healthiness
• heartiness
• robustness
• sap
• soundness
• verdure
• wellness
• wholeness
• wholesomeness

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

Reiten’s return to full fitness before the end of the domestic season is a huge plus for Norway. —Megan Feringa, New York Times, 22 June 2025

Here’s what experts had to say about the new study, plus how to incorporate these three exercises into your fitness routine for the maximum brain boost. —Elizabeth Yuko, Health, 20 June 2025

Nearly six months after Joe Biden left the White House, Senate Republicans kicked off Wednesday the first in what's expected to be a series of congressional hearings this year on his mental fitness in office. —Arkansas Online, 19 June 2025

Brad’s been following Adam Hoad, a British cooking and fitness coach, whose easy, nutritious and flavorful recipe videos proliferate on social media. —Judy Bart Kancigor, Oc Register, 19 June 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