Supporter of sport? (3)
I believe the answer is:
tee
This could be a double definition.
'supporter' is the first definition.
(a golf tee acts as a support)
'sport?' is the second definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'of' is the link.
Can you help me to learn more?
(Other definitions for tee that I've seen before include "Stand" , "Golf ball support" , "Golf-peg" , "Drive off it, half-tittering" , "Golfer's support" .)