Stress follows before a claim (10)
I believe the answer is:
pretension
'a claim' is the definition.
(I know that pretension is a type of claim)
'stress follows before' is the wordplay.
'stress' becomes 'tension' (synonyms).
'follows' is a charade indicator (letters next to each other).
'before' becomes 'pre' (prefix meaning 'before').
'tension' put after 'pre' is 'PRETENSION'.
(Other definitions for pretension that I've seen before include "Show" , "Spurious claim, aspiration" , "A claim or aspiration (to something)" , "The ostentation" , "false claim" .)