College organ is stuck (5)
I believe the answer is:
clung
'is stuck' is the definition.
(I've seen this in another clue)
'college organ' is the wordplay.
'college' becomes 'c'.
'organ' becomes 'lung' (lung is a kind of organ).
'c'+'lung'='CLUNG'
(Other definitions for clung that I've seen before include "Held on tightly" , "Held on desperately" , "Held on tight" , "Was emotionally close" .)