Source : Webster's Revised Unabridged Dictionary (1913)

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}.]