fitness
Americannoun
-
capability of the body of distributing inhaled oxygen to muscle tissue during increased physical effort.
-
Also called Darwinian fitness. Biology.
-
the genetic contribution of an individual to the next generation's gene pool relative to the average for the population, usually measured by the number of offspring or close kin that survive to reproductive age.
-
the ability of a population to maintain or increase its numbers in succeeding generations.
-
noun
-
the state of being fit
-
biology
-
the degree of adaptation of an organism to its environment, determined by its genetic constitution
-
the ability of an organism to produce viable offspring capable of surviving to the next generation
-
Other Word Forms
Noun Inflected Forms
Etymology
Origin of fitness
Explanation
Fitness is good physical condition. If you're a fitness nut and you're constantly working out, everybody else at the gym might be eyeing your sculpted muscles with envy and marveling at your stamina and strength. Fitness can also refer to your being fit, or qualified, for something. If you show up in ragged jeans and a dirty t-shirt to interview for a job in the clean room of a microchip factory, your interviewer might question your fitness for the position. For a ship, fitness is a measure of whether it's seaworthy. In biology, an organism's fitness for a particular environment is its ability to survive and reproduce in those conditions.
Vocabulary lists containing fitness
Word Generation Science - Life Science
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Physical Education - Introductory
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Exercise Vocabulary
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Beyond improving cardiovascular fitness, new research suggests that moderate aerobic exercise reshapes the nerves that regulate the heart.
From Science Daily ● Jul. 14, 2026
Trump responded to the broader conversation about age and fitness by highlighting his own health.
From Salon ● Jul. 12, 2026
Marc Guehi has won his fitness race and is expected to start England's World Cup quarter-final against Norway alongside the recalled John Stones in central defence.
From BBC ● Jul. 11, 2026
Watch personal-tech columnist Nicole Nguyen review the pluses and minuses of all the new hot wearable fitness trackers.
From The Wall Street Journal ● Jul. 10, 2026
“Don’t start, Mary—there’s nothing wrong with teaching children about fitness and health.”
From "A Good Kind of Trouble" by Lisa Moore Ramée
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
