Couple seen in quiet wood (3)
I believe the answer is:
two
'couple' is the definition.
(a couple can mean two of something)
'in quiet wood' is the wordplay.
'in' indicates the answer is hidden within the clue.
'TWO' is hidden in the letters of 'quiet wood'.
'seen' is the link.
(Other definitions for two that I've seen before include "1 + 1" , "Even number" , "'It takes ? to tango'" , "Cat's coat" , "Number in company, some say" .)