Confine to silence (4,2)
I believe the answer is:
shut up
I believe this is a double definition.
'confine' is the first definition.
(I know that shut up is a kind of confine)
'silence' is the second definition.
(I know that silence can be written as shut up)
'to' is the link.
(Other definitions for shut up that I've seen before include "close completely?" , "Stop talking - close the shop" , "Rude order to stop talking" , "Imprisoned" , "Button it!" .)