Singer Kristofferson (4)
I believe the answer is:
kris
'singer kristofferson' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for kris that I've seen before include "-- Kringle, Santa Claus" , "Malay dagger, wavy blade" , "Indonesian dagger; sounds like fold" , "Malay knife" , "weapon" .)