Buster, in silent movies, is to take a tongue-tied part (6)
I believe the answer is:
keaton
'buster in silent movies' is the definition.
'keaton' can be an answer for 'buster' (I've seen this in another clue). I'm not sure about the 'in silent movies' bit.
'take a tongue-tied part' is the wordplay.
'part' says the answer is hidden in the clue.
'KEATON' is hidden in the letters of 'take a tongue tied'.
'is to' is the link.
Can you help me to learn more?
(Other definitions for keaton that I've seen before include "Diane, Michael or Buster!" , "Buster -, silent film comedian" , "Buster - - , US comic" , "Buster ---, silent film comic" , "Buster ...... was poker-faced star of silent screen" .)