A blemish is superficial; a flaw or taint is in structure or substance. In the moral sense, we speak of a blot or stain upon reputation; a flaw or taint in character.

J. C. Fernald, English Synonyms and Antonyms (1914)

Example sentences

fault Tom's actions aren't my fault. Just remember that.
weakness You should not take advantage of others' weakness.
defect There must be a defect in the experimental method.
imperfection Imperfection is part of being human.
breach Did the hackers breach the cybersecurity defenses?
uproar This has caused a huge uproar in the city.

Popularity over time

Word	1850 → 2019	Trend
flaw		steady
fault		steady
weakness		rising
defect		steady
imperfection		steady
breach		steady

Use in printed books, per decade from 1850 to 2019.

By length

3 letters: sin¹
4 letters: vice¹, rent¹, rift¹
5 letters: break¹, fault¹, crack¹, minus², taint¹, chasm², cleft¹, chink¹
6 letters: breach¹, defect², uproar², flurry², tumult²
7 letters: opening³, rupture², quarrel², fissure², frailty²
8 letters: weakness², fracture²
10 letters: deficiency⁴
11 letters: shortcoming³
12 letters: imperfection⁴
13 letters: vulnerability⁶

The small number after each word is its number of syllables (minus² = 2 syllables).

In other languages

Français: défaut
Deutsch: Makel