In front, I'm extremely sharp (2,4)
I believe the answer is:
on time
'sharp' is the definition.
(thesaurus)
'in front i'm extremely' is the wordplay.
'in' says the answer is hidden in the clue.
'ON TIME' can be found hidden inside 'front im extremely'.
(Other definitions for on time that I've seen before include "without delay" , "as expected" , "Arriving when due" , "according to schedule" , "(Of train) not late" .)