What does flab mean?
Flab is an informal term for soft, loose flesh on the human body — the untoned layer of fat that accumulates when muscle is unused or weight is gained. Unlike neutral anatomical terms such as "adipose tissue," flab carries a distinctly negative connotation: it is almost always something people want to lose, whether through exercise, dieting, or toning routines. The word functions as a mass noun, so it has no plural form; one speaks of "some flab" or "a bit of flab," most often around the waist, arms, or chin. Beyond the physical sense, flab has developed a lively figurative use, describing any excess that ought to be trimmed — verbose prose, bloated budgets, or inefficiencies in an organization are all said to have "flab" that needs cutting. The noun arose as a back-formation from the older adjective "flabby," meaning soft and limp, and its vividness keeps it a staple of gym culture and everyday talk alike.
nounSoft, loose flesh on a person's body; unwanted body fat that is not firm or toned.
- Soft, loose, untoned flesh on the body; surplus body fat regarded as unsightly or undesirable.
"After months away from the gym, he was determined to work off the flab around his waist."
"Swimming three times a week helped her tighten up the flab under her arms."
"The editorial cut the essay's flab, trimming it from 3,000 words to a lean 1,800."
Flab is a mass (uncountable) noun and does not take a plural; quantity is expressed as "some flab," "a lot of flab," etc.
"There was still some flab around his middle despite the new diet."
"Flab" wasn't coined on its own — it's a back-formation: people shaved the ending off "flabby" to name the stuff itself.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of flab
"Flab" is a back-formation from "flabby," an adjective attested by the late eighteenth century meaning soft, limp, and out of condition; speakers simply clipped the adjective's ending to create a noun for the substance itself. The ultimate origin of "flabby" is uncertain — it may be related to "flap" or to other words for loose, dangling things — so no confident deeper root can be traced. Because the word arose within English rather than being borrowed, it has no true foreign cognates.
Related word forms
How flab is actually used
Informal and often pejorative; it carries a judgmental tone when applied to people's bodies, so it should be used with care. It is an uncountable (mass) noun with no conventional plural. By metaphorical extension, "flab" is also used informally for wordy, unnecessary content in writing or business plans (e.g., "cut the flab"). More common in British usage than American, though understood everywhere in the English-speaking world.
Easily confused with flab
A slab is a large, flat, thick piece of stone, wood, or other material, whereas flab is soft, loose body flesh.