know-it-all /ˈnowətˌɑːl/ noun plural know-it-alls
plural know-it-alls
Learner's definition of KNOW-IT-ALL
[count] informal + disapproving
: a person who talks and behaves like someone who knows everything自以为无所不知的人 —
often used before another noun常用于另一名词前 — called also (British) know-all