Chap gets record aid (4)
I believe the answer is:
help
'aid' is the definition.
(I know that aid can be written as help)
'chap gets record' is the wordplay.
'chap' becomes 'he'.
'gets' means one lot of letters go next to another.
'record' becomes 'lp' (abbreviation for long play record).
'he'+'lp'='HELP'
(Other definitions for help that I've seen before include "Serve" , "SOS, mayday" , "Hit from Band" , "Take what you want" , "Be of service" .)