Mildly, Vulgar Synonym of know-it-all, an obnoxious clever person or a person making obnoxious efforts to seem clever by acting or behaving as if they know everything.
2
Mildly, Vulgar An insolent person, especially one who makes snide remarks.
Slang Related to or characteristic of a smartass; irritatingly clever or smug.
I have had quite enough of your smartass remarks.
"That is heresy!" Reb Shimon exclaimed, and then added, "Where do you get such smartass opinions?"2019, Abby Chava Stein, Becoming Eve, Seal Press, page 64:
smartass
verb
Etymology From smart + -ass.
1
Slang To talk like a smartass, with a lot of snide remarks.
I smartassed and smack-talked half of the interview, but as I relaxed a bit more and genuinely talked with them, a strange thing happened.2012, Storm Large, Crazy Enough: A Memoir: