Former college girl reportedly supplying synthetic material (9)
I believe the answer is:
polyester
'synthetic material' is the definition.
(I know that polyester is a type of synthetic fiber)
'former college girl' is the wordplay.
'former college' becomes 'poly' (polytechnic).
'girl' becomes 'ester' ().
'poly'+'ester'='POLYESTER'
'reportedly supplying' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for polyester that I've seen before include "Man-made fibre" , "Synthetic compound" , "Synthetic fibre or substance" , "Stole prey (anag) - synthetic material" , "Synthetic textile" .)