Horowitz or Nabokov (8)
I believe the answer is:
vladimir
I believe this is a double definition.
'horowitz' is the first definition.
(I know that horowitz given name Vladimir)
'nabokov' is the second definition.
(I know that nabokov given name Vladimir)
(Other definitions for vladimir that I've seen before include "Lenin's given name" , "First name of Lenin; Russian saint" , "theatrical "waiter"" , "The V of V.I. Lenin" , "Character of play" .)