Aam \Aam\ ([add]m or [aum]m), n. [D. aam, fr. LL. ama; cf. L. hama a water bucket, Gr. ?] A Dutch and German measure of liquids, varying in different cities, being at Amsterdam about 41 wine gallons, at Antwerp 361/2, at Hamburg 383/4. [Written also Aum and Awm.]

Source: Webster's Revised Unabridged Dictionary (1913)