Bishop to walk to find blackberry (7)
I believe the answer is:
bramble
'blackberry' is the definition.
(I've seen this before)
'bishop to walk' is the wordplay.
'bishop' becomes 'b' (abbreviation used in chess).
'to walk' becomes 'ramble' (ramble is a kind of walk).
'b'+'ramble'='BRAMBLE'
'to find' is the link.
(Other definitions for bramble that I've seen before include "Briar" , "Prickly plant yielding blackberries" , "Thorny bush" , "Wild thorny shrub" , "Wild blackberry bush" .)