Plant in woods is a legume (5)
I believe the answer is:
sisal
'plant' is the definition.
The answer is an example.
'in woods is a legume' is the wordplay.
'in' indicates a hidden word.
'SISAL' can be found hidden inside 'woods is a legume'.
(Other definitions for sisal that I've seen before include "Plant fibre used for making rope" , "Rope fibre from leaves of tropical plant" , "Hemp fibre" , "Plant producing rope" , "Type of fibre" .)