/vat/ , n. , v. , vatted, vatting .
n.
1. a large container, as a tub or tank, used for storing or holding liquids: a wine vat.
2. Chem.
a. a preparation containing an insoluble dye converted by reduction into a soluble leuco base.
b. a vessel containing such a preparation.
v.t.
3. to put into or treat in a vat.
[ bef. 1100; ME (south); OE faet vessel; c. ON fat vessel, G Fass keg ]