What a heavyweight may be in a match (5)
I believe the answer is:
light
This clue might be a double definition.
'what a heavyweight' is the first definition.
(thesaurus)
'be in a match' is the second definition.
'light' can be an answer for 'match' (light can mean a flame or match). I am not certain of the 'be in a' bit.
'may' acts as a link.
Can you help me to learn more?
(Other definitions for light that I've seen before include "skedaddle!" , "Pale" , "Frivolous -- insubstantial" , "Not heavy; illuminate" , "Illumination weights little" .)