Game explorer (4)

I believe the answer is:

polo

I believe this is a double definition.

'game' is the first definition.
(polo is a kind of game)

'explorer' is the second definition.
(13th-century explorer Marco Polo)

(Other definitions for polo that I've seen before include "Team game played with horses" , "Game played on horseback wielding mallets" , "Oriental visitor < ? Sucker having a hole" , "Ball game played on horseback" , "car?" .)

I've seen this clue in The Globe and Mail, The Telegraph, The Guardian and The Times.

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