Lewis & Short

mulctra, ae, f. [mulgeo], a milkingpail, milk-pail.

  1. I. Lit.: bis venit ad mulctram, Verg. E. 3, 30: e mulctrā recens caseus, Col. 8, 17, 13; cf. mulctrum.
  2. II. Transf., the milk in a milk-pail, Col. 7, 8, 1; cf. mulctrum.