Supply with joke at end of programme (5)
I believe the answer is:
equip
'supply with' is the definition.
(I've seen this before)
'joke at end of programme' is the wordplay.
'joke' becomes 'quip' (quipping is a kind of joking**).
'at' means one lot of letters go next to another (I've seen this in other clues).
'end of' says to take the final letters.
The last letter of 'programme' is 'e'.
'quip' after 'e' is 'EQUIP'.
(Other definitions for equip that I've seen before include "Fit out, supply" , "Supply (with kit)" , "Provide with items (for particular task)" , "Accoutre" , "Furnish with requirements" .)