Tuns meaning : A large cask; an oblong vessel bulging in the middle, like a pipe or puncheon, and girt with hoops; a wine cask. A fermenting vat. An old English measure of capacity for liquids, containing 252 wine gallons; equal to two pipes. A weight of 2,240 pounds. An indefinite large quantity. A drunkard. Any shell belonging to Tonna and allied genera. The cryptobiotic state of a tardigrade, when its metabolism is temporarily suspended. To put into tuns, or casks. A part of the ancient Maya Long Count Calendar system which corresponds to 18 winal cycles or 360 days.