Help individual to crack nuts (4)
I believe the answer is:
maid
'help' is the definition.
(I've seen this in another clue)
'individual to crack nuts' is the wordplay.
'individual' becomes 'i' (Roman numeral for one).
'to crack' means one lot of letters goes inside another (inserted letters crack into others).
'nuts' becomes 'mad' (I've seen this in other clues).
'i' going within 'mad' is 'MAID'.
(Other definitions for maid that I've seen before include "daughter?" , "One in service" , "employee" , "Young woman - servant" , "Female domestic servant" .)