Flawless means without a single visible fault. A flawless performance, flawless skin, flawless English.
It claims perfection in execution rather than in conception: a flawless performance of a mediocre piece is possible. In gemmology it is a graded technical term — a flawless diamond has no inclusions visible at ten times magnification, and the grade is worth a great deal of money. Note flawlessly; and that flaw originally meant a flake or splinter, which is why it suits stone.
1adjectiveflawlessWithout a single visible fault.
“Her English is flawless; you'd never guess it isn't her first language.”
synonyms: perfect, impeccable
flawless is a quality of perfection.
Flaw plus -less. Flaw came from Old Norse flaga, a flake or slab, so a flaw was originally a splinter in stone — which is exactly the sense the diamond grade preserves.
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
flaw
English, today
flawless
Built from
From flaw + less. flaw comes 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