Swiss painter king sheltered (4)
I believe the answer is:
klee
'swiss painter' is the definition.
(Paul Klee, 1879-1940)
'king sheltered' is the wordplay.
'king' becomes 'K' (abbreviation for king in chess).
'sheltered' becomes 'lee' (as in lee side, the side sheltered from wind).
'k'+'lee'='KLEE'
(Other definitions for klee that I've seen before include "Paul - - , Swiss painter" , "Auction offerer" , "Paul ---, Swiss artist" , "Paul --, Swiss surrealist" .)