Stuff found below position (9)
I believe the answer is:
substance
'stuff' is the definition.
(I know that substance is a type of stuff)
'below position' is the wordplay.
'below' becomes 'sub'.
'position' becomes 'stance' (stance is a kind of position).
'sub'+'stance'='SUBSTANCE'
'found' is the link.
(Other definitions for substance that I've seen before include "wealth" , "Physical matter" , "Basic matter" , "power" , "Matter or material that a thing is made of" .)