Mini-Me is pissed ... with Verne Troyer blasting UFC star Jon Jones for using the M-word to attack Daniel Cormier ... a word that's clearly offensive to little people.
Jones hurled the insult at Cormier during their Twitter war this week -- calling him a "mental m**get"
Troyer says the word is extremely hurtful -- adding that people who use that word are "just naive and I would say stupid."
Troyer says he doesn't necessarily want an apology -- he just wants Jones to stop using the word.