Bridge game (7)

I believe the answer is:

pontoon

I'm a little stuck... Click here to teach me more about this clue!

But I can't explain it at all! Could you help me understand?

(Other definitions for pontoon that I've seen before include "Gambling game" , "It spans" , "Card game; floating support" , "Half of 1D [GAME OR BIRD]" , "Flat-bottomed boat supporting bridge" .)

I've seen this clue in The Telegraph and the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.