It's better to be under this than below it (3)
I believe the answer is:
'it's better to be under this than below it' is the definition.
The definition suggests a singular noun which matches the answer.
This is the entire clue.
Can you help me to learn more?
(Other definitions for par that I've seen before include "Normal golfing score" , "standard for course" , "Rap for being average" , "Expected golf hole score" , "A number of golfing" .)