Is There a Card Game Called "Hoss"? Likely H.O.R.S.E. Poker
No widely known card game is named "Hoss." It's likely one of the following:
Misspelling of Horse: Basketball shooting game (H-O-R-S-E), sometimes played with cards as a drinking game variant.
Misspelling of Hase / Hasi: German for "Hare" – not a standard game.
Regional / Family Game: A house-rule variant of Poker, Rummy, or Golf called "Hoss" locally.
Slang: "Hoss" = friend/buddy (Southern US). "Let's play a hand, hoss."
Pop Culture Reference:Bonanza character Hoss Cartwright – maybe a poker scene inspired a nickname.
H.O.R.S.E. Poker: Mixed game rotation: Hold'em, Omaha, Razz, Stud, Eight-or-better (Stud Hi/Lo). This is the most likely match if you saw it in a poker context.
If You Can Provide:
Where you heard/read it (book, movie, stream, relative).
Number of players, deck type, any rules you recall.
Region / language context.
I can identify the exact game. H.O.R.S.E. Poker is the strongest candidate for a structured "game" with that name.