Webster's Revised Unabridged Dictionary · 1913

Tun

Tun (tun) , noun

[Anglo-Saxon 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.
(Commerce) A weight of 2,240 pounds. See Ton. [Rare]
5.
An indefinite large quantity. — Shakespeare
A tun of man in thy large bulk is writ. — Dryden
6.
A drunkard; -- so called humorously, or in contempt.
7.
(Zoology) Any shell belonging to Dolium and allied genera; -- called also tun-shell.

Tun , transitive verb

To put into tuns, or casks. — Boyle