Mountaineer forks out pounds for a term at Oxford (6)
I believe the answer is:
hilary
'a term at oxford' is the definition.
(an academic term at the University of Oxford)
'mountaineer forks out pounds' is the wordplay.
'mountaineer' becomes 'hillary' (mountaineer Edmund Hillary).
'forks out' is a deletion indicator.
'pounds' becomes 'L' (L can represent the monetary pound).
'hillary' with 'l' taken away is 'HILARY'.
'for' acts as a link.
(Other definitions for hilary that I've seen before include "Boy's or girl's name" , "University term" , "Term < for a girl" , "The Spring legal term" , "girl or boy" .)