Yet it's quiet (5)
I believe the answer is:
still
I believe this clue is a double definition.
'yet' is the first definition.
(I know that yet can be written as still)
'quiet' is the second definition.
(I know that still is a type of quiet)
'it's' is the link.
(Other definitions for still that I've seen before include "gentle" , "not bubbly" , "'Quiet!'" , "source of spirits" , "in spite of this" .)