cualquiera
/kwalˈkjeɾa/ · A2 · pron
anyone, whoever, whomever
cual + quiera = which + you may want: whichever you want, so anyone
Built from cual (which) and quiera, the subjunctive of querer (to want). Literally whichever one you might want, so it means any or anyone. Said of a person, un cualquiera is just anybody: a nobody.