The Collaborative International Dictionary of English v.0.48:

Mazer \Maz"er\, n. [OE. maser, akin to OD. maser an excrescence
   on a maple tree, OHG. masar, G. maser spot, Icel. m["o]surr
   maple.]
   A large drinking bowl; -- originally made of maple. [Obs.]
   [1913 Webster]

         Their brimful mazers to the feasting bring. --Drayton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mazer
    n 1: a large hardwood drinking bowl