felicidad
/feliθiˈdad/ · A2 · noun · f
happiness
feliz (happy) + -dad (-ity) = felicity, from Latin felicitas
English felicity is the same word: Latin felicitas, from felix (lucky, happy). Spanish -dad matches English -ity (ciudad/city, verdad/verity), and the z of feliz turns to c before i. Feminine, like all -dad nouns.