Polish king receives one Cubist (5)
I believe the answer is:
rubik
'cubist' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'polish king receives one' is the wordplay.
'polish' becomes 'rub' (polish meaning rub to make shiny).
'king' becomes 'K' (chess abbreviation).
'receives' means one lot of letters goes inside another (inserted letters are received).
'one' becomes 'i' (Roman numeral).
'rub'+'k'='rubk'
'rubk' enclosing 'i' is 'RUBIK'.
Can you help me to learn more?
(Other definitions for rubik that I've seen before include "The cube man" , "Puzzle cube inventor" , "Inventor of a famous cube" .)