Deck game taken up crossing river (5)
I believe the answer is:
orlop
'deck' is the definition.
(a deck on a ship)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for orlop that I've seen before include "Lowest deck of a wooden sailing ship" , "part of ship" , "hold covering" , "deck at the lowest point" , "Ship's lowest deck" .)