Paco \Pa"co\, Pacos \Pa"cos\, n. [Sp. paco, fr. Peruv. paco. Cf. {Alpaca}.] 1. (Zo["o]l.) Same as {Alpaca}. 2. [Peruv. paco, pacu, red, reddish, reddish ore containing silver; perh. a different word.] (Min.) An earthy-looking ore, consisting of brown oxide of iron with minute particles of native silver. --Ure.