Call hospital department that is nursing tense student (7)
I believe the answer is:
entitle
'call' is the definition.
(I know that entitle is a kind of call)
'hospital department that is nursing tense student' is the wordplay.
'hospital department' becomes 'ENT' (Ear, Nose and Throat department).
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'nursing' means one lot of letters goes inside another.
'tense' becomes 't' (grammatical abbreviation).
'student' becomes 'L' (as in L-plates for learner drivers).
't'+'l'='tl'
'ie' placed around 'tl' is 'itle'.
'ent'+'itle'='ENTITLE'
(Other definitions for entitle that I've seen before include "Allow" , "Call; permit" , "Give a right (to someone to do something)" , "Furnish with a right or claim" , "Qualify, empower" .)