Comment by apgwoz
“Poker is a family of _comparing_ card games in which players _wager_ over which hand is best according to that specific game’s rules.”
— [WikiPedia](https://en.wikipedia.org/wiki/Poker)
I don’t think I would have gone for that definition, but now that I see it, it sums up everything I’ve ever known “Poker” to be. The game is won by comparing cards you have left (meaning that Rummy, Go Fish, or Bridge are different), and there’s a wager about the game (possibly just bragging rights if not playing for money).
I totally agree, but I stand by the opinion that imperfect-information bit is so essential that it's simply assumed (it's, naturally, not specific to just poker card games, though). If you come to the table with your own stack of cards to draw from, it's very likely going to end badly for you, depending on how transparent you're with the matter.