smarty-pants

[ smahr-tee-pants ]

noun

, (used with a singular verb)

1. smart aleck:

   He's just a smarty-pants, showing off for some girls.

2. a smart person:

   My kid is a super smarty-pants who continues to get 4s on her state exams.

3. (used as a mildly abusive term of address or to refer to someone with contempt):

   Who invited that smarty-pants--everyone hates her!

smarty-pants

/ ˈsmɑːtɪˌbuːts; ˈsmɑːtɪˌpænts /

noun

1. informal.
   functioning as singular a would-be clever person

Word History and Origins

Origin of smarty-pants¹

First recorded in 1915–20

Example Sentences

Republican strategists have for years skewered smarty-pants Democrats as Ivy League elitists—often with good reason.

From The Daily Beast