Chekhov, say, heading off from part of Switzerland (5)
I believe the answer is:
anton
'chekhov' is the definition.
(I've seen this before)
'heading off from part of switzerland' is the wordplay.
'heading off from' means to remove the first letter.
'part of switzerland' becomes 'canton' (Swiss administrative subdivision).
'canton' with its initial letter taken away is 'ANTON'.
'say' is the link.
(Other definitions for anton that I've seen before include "..... Chekov" , "Chekhov, say" , "man" , "Rodgers perhaps" , "-- Chekhov, Russian dramatist" .)