Convict turned up with raw material in abundance (6)
I believe the answer is:
galore
'in abundance' is the definition.
(thesaurus)
'convict turned up with raw material' is the wordplay.
'convict' becomes 'lag' (I've seen this before).
'turned up' says the letters should be written in reverse.
'with' is a charade indicator (letters next to each other).
'raw material' becomes 'ore' (I've seen this before).
'lag' in reverse letter order is 'gal'.
'gal'+'ore'='GALORE'
(Other definitions for galore that I've seen before include "Existing in great numbers" , "Lots of" , "Aplenty" , "Lo, Reg, a change could be in abundance" , "In profusion" .)