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

Many companies that once relied solely on fitness apps or gym memberships are expanding into more integrative care. —Irina Logman, Forbes.com, 10 June 2025

The resort will have a full-service spa, a fitness center, an indoor thermal pool, a cold plunge, a sauna and steam rooms. —Amaia Gavica, Idaho Statesman, 8 June 2025

The Premier League also has a battery of fitness tests that players, from under-12 up, complete each season. —Liam Tharme, New York Times, 7 June 2025

The common areas—like the spa, fitness center, restaurants, and pool—are wheelchair-accessible, with elevators and ramps readily available throughout the hotel. —Susmita Baral, Travel + Leisure, 7 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