Smart leaders of American college hiding expenses (4)
I believe the answer is:
ache
'smart' is the definition.
(synonyms)
'leaders of american college hiding expenses' is the wordplay.
'leaders of' says to take the initial letters.
The initial letters of 'american college hiding expenses' is 'ACHE'.
(Other definitions for ache that I've seen before include "Hurt; yearn" , "burn" , "Persistent dull pain" , "A dull lingering pain" , "Play up" .)