Proust ran off in a daze (6)
I believe the answer is:
stupor
'in a daze' is the definition.
(I've seen this before)
'proust ran' is the wordplay.
'ran' indicates an anagram (letters have run around).
'proust' anagrammed gives 'STUPOR'.
'off' is the link.
(Other definitions for stupor that I've seen before include "Stupefaction, daze" , "State of lethargy" , "Daze or torpor" , "Shocked or drunken state" , "Proust found in dazed condition" .)