Befuddled actor has no time for killer whale (4)
I believe the answer is:
orca
'for killer whale' is the definition.
(synonyms)
'befuddled actor has no time' is the wordplay.
'befuddled' indicates anagramming the letters.
'has no' is a deletion indicator.
'time' becomes 't' (abbreviation).
'actor' with 't' taken out is 'acor'.
'acor' is an anagram of 'ORCA'.
(Other definitions for orca that I've seen before include "swimmer in black and white" , "Killer in deep" , "Sea creature" , "grampus" , "Cor! a killer whale" .)