Generous measure for Sasquatch (7)
I believe the answer is:
bigfoot
'for sasquatch' is the definition.
(synonyms)
'generous measure' is the wordplay.
'generous' becomes 'big' (similar in meaning).
'measure' becomes 'foot' (foot is a kind of measure).
'big'+'foot'='BIGFOOT'
(Other definitions for bigfoot that I've seen before include "Supposed American ape" , "American 'apeman'" , "Fabled hairy primate" , "Supposed NW US ape-like creature" , "Supposed ape of northwest US" .)