-dad . ( Of the lat. )( -tas, - atis ). 1. suf. It means 'quality' in abstract nouns derived from adjectives. If the adjective base is bisílabo, usually take the form -age. Mocedad, short-sightedness, stubbornness. Also take it finished adjectives in -io. Dirt, compulsory, precarity. If the adjective is more than two syllables, takes in general, the form -idad. Outrage, hearty, effectiveness. The form -dad appears only behind l or n. Lightness, evil, ruindad . When -dad applies to verbal adjectives in -ble, form finished products in -liability. Guilt.