Stimulate at 54 points (5)
I believe the answer is:
liven
'stimulate' is the definition.
(livening is a kind of stimulating)
'at 54 points' is the wordplay.
'at' is a charade indicator (letters next to each other).
'54' becomes 'liv' (Roman numerals).
'points' becomes 'en' (compass points east and north).
'liv' put next to 'en' is 'LIVEN'.
(Other definitions for liven that I've seen before include "Vitalise" , "Make active" , "Make animated" , "Invigorate" , "Cause excitement" .)