Settle in garrison (6)
I believe the answer is:
occupy
This clue is a double definition.
'settle in' is the first definition.
(thesaurus)
'garrison' is the second definition.
(thesaurus)
(Other definitions for occupy that I've seen before include "Reside in; keep busy" , "Take possession of" , "Live in a space" , "Give cursory look over" , "Hold (a position) keep (someone) busy" .)