Carta (KAR-ta) = menu — I think it’s more popular to ask for el menú in Latin America. However, in Spain, el menú refers to the daily special (menú del día), so if you want a menu that lists all the food they offer at a café/tapas bar/restaurant in Spain, ask for la carta.
Ganga (GAN-ga) = the official translation is “bargain” — but it can also be a slang term meaning “a much-desired item”
Chollo (CHO-yo) = a bargain; something cheap; something of great benefit acquired with little effort
La Leche (la LEH-cheh) = awesome/cool/the bomb (e.g: ¡Paris es la leche! = “Paris is the bomb!”) — Literal translation: “the milk”
La Marcha (la MAR-cha) = nightlife (e.g. Salir de marcha = to go out/to party)
Montarla gorda (mon-TAR-la GOR-da) = to party hard, or as the young people like to say, “go hard.” — Literal translation means to “mount the fat.” Don’t ask; I don’t get it either. Used in a sentence: ¡Mañana la vamos a montar gorda!