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nona f. (Noun) "grandma"

13th cent. Borrowed from Latin nonna "old woman," "wet nurse." Also note 12th cent. Old Spanish nana "married woman."

Romance: Western Vulgar Latin: French nonne, Italian nonna

Despite the semantic argument that the word is native to Spanish, and not borrowed from Latin, the word did not undergo palatalization. Fascinatingly, a cousin of the word is ñoño, which palatalized twice - generally against the norm in Spanish.