Other forms: flaws
A flaw is the one thing wrong with something otherwise good — a hairline crack in a vase, a cloudy speck inside a diamond, a snag running down a new pair of tights. Small enough to miss at first, big enough to spoil it once you have seen it.
Arguments and plans have flaws too, and that is where you will meet the word most: a flaw in the reasoning, a fatal flaw in the design, a flaw in the safety case that nobody spotted for years. People have them as well — a character flaw is a weakness in someone otherwise decent. It takes IN: a flaw in the glass, a flaw in the plan. The adjectives are flawed and flawless. And a flaw sits in the thing itself; a mistake you made is an error.
1nounflawA fault or mark that spoils something otherwise good.
“The vase was half price because of a flaw near the rim.”
2nounweakA weak point in an argument, a plan or a person's character that makes it fail.
“There is one flaw in the plan: nobody has the key.”
flaw is a fault.
Also accepted in games: defect, imperfection
A flaw was once a flake. Middle English flawe meant a splinter, or a flake of snow or fire, probably taken from Old Norse flaga, a slab of stone or a flake, and behind that Proto-Germanic *flagō, a layer of soil, from a Proto-Indo-European root *plok- meaning broad and flat. The chip that broke off gave its name to the mark it left behind.
Proto-Indo-European
*plok- — broad, flat
Proto-Germanic
*flagō — a layer of soil
Old Norse
flaga — a flag or slab of stone, flake
Middle English
flawe
English, today
flaw
Built from
From Middle English flawe, flay (“a flake of fire or snow, spark, splinter”), probably from Old Norse flaga (“a flag or slab of stone, flake”), from Proto-Germanic flagō (“a layer of soil”), from Proto-Indo-European plok- (“broad, flat”). Cognate with Icelandic flaga (“flake”), Swedish flaga (“flake, scale”), Danish flage (“flake”), Middle Low German vlage (“a layer of soil”), Old English flōh (“a fragment, piece”).
Etymology from Wiktionary, CC BY-SA