espertinho

Etymology
From.

Noun

 * 1) smarty pants; know-it-all someone who obnoxiously claims to be knowledgeable
 * 2) a sly, cunning person
 * 1) a sly, cunning person

Adjective

 * 1)  who obnoxiously claims to be knowledgeable
 * 2)  sly; cunning; wily
 * 1)  sly; cunning; wily