Party time hit (3)
I believe the answer is:
dot
'hit' is the definition.
(dot can informally mean to hit someone)
'party time' is the wordplay.
'party' becomes 'do' (do is a kind of party).
'time' becomes 't' (abbreviation).
'do'+'t'='DOT'
(Other definitions for dot that I've seen before include "A point, small round mark" , "Spot, speck" , "Tiny speck" , "One signal used in Morse code" , "Morse symbol; spot" .)