Flabby means soft, loose, and lacking firmness. When something is flabby, it jiggles or sags instead of staying firm and tight. You might notice that muscles become flabby when they're not used regularly: an athlete who stops training may find their once-strong arms becoming soft and weak.

The word often describes parts of the body, but it applies to other things too. A flabby argument in a debate is one that's weak and unconvincing, full of holes that opponents can easily poke through. Flabby writing uses too many unnecessary words and lacks the strength of clear, direct sentences. When a story has a flabby middle, it drags on without much happening, losing the reader's attention.

The word carries a negative feeling: flabbiness suggests something that should be stronger or tighter but isn't. Think of the difference between a firm, ripe peach and one that's gone soft and mushy. That mushiness, that lack of structure and strength, captures what flabby means. Whether describing muscles, arguments, or even organizations that have lost their edge, flabby means weakness where there should be strength.