Crossword Genius

Small tree used to make window frame (4)

Ross

I believe the answer is:

sash

'window frame' is the definition.
(thesaurus)

'small tree' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'tree' becomes 'ash' (ash is a kind of tree**).
's'+'ash'='SASH'

'used to make' is the link.

(Other definitions for sash that I've seen before include "Decorative belt" , "Band worn over shoulder or round waist" , "Baldrick" , "Band of cloth" , "Long strip of material - window frame" .)

I've seen this clue in The Times.
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