»tun

tun |tən| a large beer or wine cask; a brewer's fermenting vat. Also an imperial measure of capacity, equal to 4 hogsheads. To store beer or wine in a tun.
Probably of Gaulish origin; from the Old English tunne, ex. medieval Latin tunna.

salim filed this under lingo at 19h06 Sunday, 30 December 2007 (link) (Yr two bits?)