Try joke (5)
I believe the answer is:
crack
This clue is a double definition.
'try' is the first definition.
(I know that crack is a type of try)
'joke' is the second definition.
(a crack is a joke or quip)
(Other definitions for crack that I've seen before include "Joke; split" , "Narrow opening, break" , "Fracture" , "find solution" , "Ace" .)