Prepare for the final jest (5)
I believe the answer is:
equip
'prepare' is the definition.
(thesaurus)
'the final jest' is the wordplay.
'final' says to take the final letters.
'jest' becomes 'quip' (quipping is a kind of jesting).
The final letter of 'the' is 'e'.
'e'+'quip'='EQUIP'
'for' acts as a link.
(Other definitions for equip that I've seen before include "Fit out, supply" , "Provide with suitable gear" , "Provide with kit" , "Furnish, fit out" , "Supply (with items)" .)