In the end, wind break would, they say, become washed up old timber (9)
I believe the answer is:
driftwood
'washed up old timber' is the definition.
'driftwood' can be an answer for 'timber' (thesaurus). I'm unsure of the 'washed up old' bit.
'in the end wind break would they say' is the wordplay.
'in the end' suggests the final letters.
'break' becomes 'rift' (rift can mean a break or opening).
'they say' shows a homophone (sound like).
The final letter of 'wind' is 'd'.
'would' is a homophone of 'wood'.
'd'+'rift'+'wood'='DRIFTWOOD'
'become' acts as a link.
Can you help me to learn more?
(Other definitions for driftwood that I've seen before include "Flotsam" , "Washed up pieces of tree" , "What beachcomber found" , "Timber, etc, on the sea" , "found washed up on a beach?" .)