Small man, university student, one for Spurs? (7)
I believe the answer is:
stimuli
'spurs?' is the definition.
(plural of stimulus, a spur or cause of something)
'small man university student one' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'man' becomes 'tim' (short for Timothy).
'university' becomes 'U' (abbreviation for university).
'student' becomes 'l' (as in L-plates for learner drivers).
'one' becomes 'i' (Roman numeral).
's'+'tim'+'u'+'l'+'i'='STIMULI'
'for' is the link.
(Other definitions for stimuli that I've seen before include "Things that cause a response" , "Promoters of activity" , "Things provoking reactions" , "Things promoting activity" , "Activity inducers" .)