IPA: //ˈkɑːrdˌpleɪər//
KK: /ˈkɑrdˌpleɪər/
A person who plays card games, often for fun or in a competitive setting.
He is a skilled cardplayer who often wins tournaments.
Cardplayer → It is formed from "card" (from Old French *carte*, meaning a piece of paper or a playing card) and "player" (from Old English *plegian*, meaning to engage in activity or play). The word "cardplayer" refers to a person who engages in playing card games.
Think of someone who is actively 'playing' ('plegian') with 'cards' ('carte') — that's what a cardplayer does.