Old stager devious viscount caught out? (7)
I believe the answer is:
ustinov
'old stager' is the definition.
(Peter Ustinov, 1921-2004)
'devious viscount caught out?' is the wordplay.
'devious' indicates anagramming the letters.
'caught' becomes 'c' (cricket abbreviation).
'out?' is a deletion indicator.
'viscount' with 'c' removed is 'visount'.
'visount' anagrammed gives 'USTINOV'.
(Other definitions for ustinov that I've seen before include "Peter --, English actor and raconteur (d.2004)" , "Peter . . . . . . ., late actor and raconteur" , "Does it suit Nov to be an actor?" , "See 22" , "Peter __, actor, playwright and raconteur, d. 2004" .)