Painter involved in yoga (4)
I believe the answer is:
goya
'painter' is the definition.
(Spanish painter Francisco Goya)
'involved in yoga' is the wordplay.
'involved in' indicates an anagram (involved can mean complex or confusing).
'yoga' with letters rearranged gives 'GOYA'.
(Other definitions for goya that I've seen before include "Ay, go to see great Spanish painter" , "Eighteenth to nineteenth century Spanish artist" , "He painted Wellington" , "Eighteenth and nineteenth century Spanish painter" , "Old master" .)