Smart alecs (4-4)
'smart alecs' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for know-alls that I've seen before include "People who behave as if they are conversant with everything" , "People who think they have encyclopedic brains" , "Smart alecs" .)
'smart alecs' is the definition.
(both can mean annoyingly clever people)
This is the entire clue.
(Another definition for wise guys that I've seen is " Smart Alecs?".)