One in a hole, at golf? (3)
I believe the answer is:
pin
'golf?' is the definition.
The definition and answer can be both related to competing as well as being verbs in their base form.
Perhaps you can see a link between them that I don't see?
'one in a hole' is the wordplay.
'one' becomes 'i' (Roman numeral).
'in' indicates putting letters inside.
'a hole' becomes 'pn' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'i' placed inside 'pn' is 'PIN'.
'at' is the link.
Can you help me to learn more?
(Other definitions for pin that I've seen before include "Initially, confidential number for use of bank card" , "Badge" , "Fixing device" , "Sewer's aid" , "Fastener; skittle" .)