Rage about kit (4)
I believe the answer is:
gear
'kit' is the definition.
(I've seen this before)
'rage about' is the wordplay.
'about' is an anagram indicator.
'rage' anagrammed gives 'GEAR'.
(Other definitions for gear that I've seen before include "Informal clothes seen in rage" , "Set of wheels working by engaging cogs" , "Equipment; dress" , "Unusually good" , "working order" .)