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-dad, -tad Suffix used to form abstract nouns from adjectives.

From Latin -tatem, accusative of -tas 'id.' From Proto-Italic *-tāts 'id.' From Proto-Indo-European *-teh2ts 'id.'

Romance: Western Vulgar Latin: Asturian -tá/i>, Portuguese -dade, Galician -dade, Catalan -tat, French , Italian -ità; Eastern Vulgar Latin: Aromanian -tati, Romanian -tate

Indo-European: Hellenic: Ancient Greek -της (tes); Indo-Iranian: Sanskrit -tāti