Sediment as a basis of justification (7)
I believe the answer is:
grounds
I believe this is a triple definition!
'sediment' is the first definition.
(as in coffee grounds)
'as' is a link.
'a basis' is the second definition.
(I've seen this in another clue)
'of' is a link.
'justification' is the third definition.
(I know that grounds is a type of justification)
(Other definitions for grounds that I've seen before include "justification" , "Dregs" , "Coffee sediment" , "enclosure around house" , "Basis for belief" .)