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.
"the oxen move but slowly, and must first drag the tun to the wine-cellar at the farm-house. But you may lead,"
Etta Blaisdell McDonald. Rafael in Italy (1910)
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a treasury; a sink, a court; a cap and bells, a favourite; a broken reed, a court of justice; an empty tun, a general; a running sore, the administration.