wise guy
US /ˈwaɪz ˌɡaɪ/
UK /ˈwaɪz ˌɡaɪ/

1.
listillo, sabelotodo, gracioso
a person who is irritating because they think they know everything and try to be clever
:
•
Don't be such a wise guy, just answer the question.
No seas tan listillo, solo responde la pregunta.
•
He always has a sarcastic comment, a real wise guy.
Siempre tiene un comentario sarcástico, un verdadero listillo.