The Collaborative International Dictionary of English v.0.48:

Stoop \Stoop\, n. [OE. stope, Icel. staup; akin to AS. ste['a]p,
   D. stoop, G. stauf, OHG. stouph.]
   A vessel of liquor; a flagon. [Written also stoup.]
   [1913 Webster]

         Fetch me a stoop of liquor.              --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Stoup \Stoup\ (st[=oo]p), n. [See Stoop a vessel.]
   1. A flagon; a vessel or measure for liquids. [Scot.]
      --Jamieson.
      [1913 Webster]

   2. (Eccl.) A basin at the entrance of Roman Catholic churches
      for containing the holy water with which those who enter,
      dipping their fingers in it, cross themselves; -- called
      also holy-water stoup or holy-water font.
      [1913 Webster]

WordNet (r) 3.0 (2006):

stoup
    n 1: an archaic drinking vessel
    2: basin for holy water [syn: stoup, stoop]