Supporter of sport? (3)

I believe the answer is:

tee

I'm a little stuck... Click here to teach me about this clue!

Here is my best explanation:

This could be a double definition.

'supporter' is the first definition.
(I've seen this in other clues)

'sport?' is the second definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.

'of' acts as a link.

Can you help me to learn more?