ˌholier-than-ˈthou adjective
showing that you think you are morally better than other people – used to show disapproval Synonym : self-righteous

[TahlilGaran] Dictionary of Contemporary English ▲

holier-than-thou
someone who is holier-than-thou behaves as if they have better morals than other people.
I can't stand that holier-than-thou attitude that some vegetarians have.

[TahlilGaran] English Idioms Dictionary ▲

holier-than-thou
acting as if one is better than others in goodness or character etc.
I do not like him because he takes a holier-than-thou attitude toward everyone else.

[TahlilGaran] English Idioms Dictionary ▲

holier than thou
adj. Acting as if you are better than others in goodness, character, or reverence for God; acting as if morally better than other people.
Most people find holier-than-thou actions in others hard to accept.
After Mr. Howard stopped smoking, he had a holier-than-thou manner toward his friends who still smoked.

[TahlilGaran] English Idioms Dictionary ▲