Ready with plain or plush fabric (8)
I believe the answer is:
cashmere
'plush fabric' is the definition.
'cashmere' can be an answer for 'fabric' (cashmere is a kind of fabric). I'm not sure about the 'plush' bit.
'ready with plain' is the wordplay.
'ready' becomes 'cash' (ready can informally mean cash).
'with' says to put letters next to each other.
'plain' becomes 'mere' (similar in meaning).
'cash'+'mere'='CASHMERE'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for cashmere that I've seen before include "knitted garment" , "'Fine, soft wool from a goat (8)'" , "Fine wool for a schemer" , "Soft fabric made from the wool of a goat" , "Soft fabric made from goats' hair" .)