Move into underwear (5)
I believe the answer is:
shift
I believe this is a double definition.
'move' is the first definition.
(I know that shift is a kind of move)
'underwear' is the second definition.
(I know that shift is a type of underwear)
'into' is the link.
(Other definitions for shift that I've seen before include "Team of workers" , "Move; straight dress" , "Simple dress; spell of work" , "Move - working period" , "Move from one position to another" .)