An enthusiastic marker of approval — anything that impresses, satisfies, or exceeds expectations gets called this.
Chido is how Mexicans express approval — a word that carries enthusiasm in a single syllable. You'd use it for anything that meets or exceeds expectations: a plan that sounds good, a person you respect, an experience that delivered. The tone is warm and genuine, the register informal but not crude. It works across ages, though it pulses strongest in youth culture.
The word arrived through Asturian immigrants in the 1800s, carrying their word "xidu" (comfortable, pleasant) into Mexican Spanish. For fifty years it lived only in speech, transforming phonetically from "xidu" to "chido" as Mexican mouths shaped it. First documented in 1904 among working-class neighborhoods, it remained marginal until the 1970s.
Then something shifted. Between 1976 and 1979, usage exploded — a 6.7x spike in three years. The countercultural movements of post-1968 Mexico turned working-class slang into generational identity. "Chido" became distinctly chilango (Mexico City), a marker of urban Mexican authenticity against formal Spanish norms. What immigrants brought, the streets transformed, and youth culture claimed as definitively Mexican.