Confine one after another we hear (6)
I believe the answer is:
'confine' is the definition.
(I know that intern is a type of confine)
'one after another we hear' is the wordplay.
'one after another' becomes 'inturn' (I've seen this in another clue).
'we hear' shows a homophone (sound like).
'inturn' is a homophone of 'INTERN'.
(Other definitions for intern that I've seen before include "Hospital worker" , "put in jail" , "Confine - person on work experience" , "Lock up the hospital doctor" , "Imprison the young doctor without trial" .)