locura
/loˈkuɾa/ · A2 · noun · f
lunacy
loco (crazy) + -ura (-ness) = craziness; the c stays hard as in loco
Spanish builds abstract nouns from adjectives with -ura: dulce → dulzura, tierno → ternura, loco → locura. If you know loco from English slang, you already own the root. Feminine: la locura. As an exclamation, ¡Qué locura! means That is insane!