Lock up (8)
'lock up' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for imprison that I've seen before include "shut up" , "put in detention" , "Put behind bars" , "Lock up" , "Put in jail" .)
'lock up' is the definition.
(thesaurus)
This is all the clue.
(Other definitions for intern that I've seen before include "22 [IMPRISON]" , "Confine the hospital resident" , "Official language of Pakistan" , "Confine the hospital doctor" , "House officer" .)