Flash character purchasing hot material (6)
I believe the answer is:
mohair
'material' is the definition.
(mohair is a kind of material)
'flash character purchasing hot' is the wordplay.
'flash' becomes 'mo' (I've seen this in other clues).
'character' becomes 'air' (I've seen this before**).
'purchasing' means one lot of letters goes inside another (some letters take possession of others).
'hot' becomes 'h'.
'mo'+'air'='moair'
'moair' going around 'h' is 'MOHAIR'.
(Other definitions for mohair that I've seen before include "Cloth made from wool of angora goat" , "Yarn provided by goats" , "coat required" , "Fabric made from the coat of an Angora goat" , "Fine silky hair of angora goat" .)