\Tun\, n. [AS. tunne. See {Ton} a weight.]
1. A large cask; an oblong vessel bulging in the middle, like
   a pipe or puncheon, and girt with hoops; a wine cask.
2. (Brewing) A fermenting vat.
3. A certain measure for liquids, as for wine, equal to two
   pipes, four hogsheads, or 252 gallons. In different
   countries, the tun differs in quantity.
4. (Com.) A weight of 2,240 pounds. See {Ton}. [R.]
5. An indefinite large quantity. --Shak.
         A tun of man in thy large bulk is writ. --Dryden.
6. A drunkard; -- so called humorously, or in contempt.
7. (Zo["o]l.) Any shell belonging to Dolium and allied
   genera; -- called also {tun-shell}.

\Tun\, v. i. [imp. & p. p. {Tunned}; p. pr. & vb. n.
{Tunning}.]
To put into tuns, or casks. --Boyle.