A golfer upset about pro's first game (8)
I believe the answer is:
leapfrog
'game' is the definition.
(I know that leapfrog is a type of child\\u0027s game)
'a golfer upset about pro's first' is the wordplay.
'upset' indicates an anagram.
'about' indicates putting letters inside.
'first' indicates taking the first letters.
The first letter of 'pros' is 'p'.
'a'+'golfer'='agolfer'
'agolfer' anagrammed gives 'leafrog'.
'leafrog' going around 'p' is 'LEAPFROG'.
(Other definitions for leapfrog that I've seen before include "Game in which one child jumps over another" , "bound over" , "Vaulting game" , "Child's game of jumping over other children" , "Overtake in position" .)