The Collaborative International Dictionary
Mash \Mash\, v. t. [imp. & p. p. Mashed; p. pr. & vb. n. Mashing.] [Akin to G. meischen, maischen, to mash, mix, and prob. to mischen, E. mix. See 2d Mash.] To convert into a mash; to reduce to a soft pulpy state by beating or pressure; to bruise; to crush; as, to mash apples in a mill, or potatoes with a pestle. Specifically (Brewing), to convert, as malt, or malt and meal, into the mash which makes wort.
Mashing tub, a tub for making the mash in breweries and distilleries; -- called also mash tun, and mash vat.
Wiktionary
n. A large tub used in making mash and wort.
Usage examples of "mash tun".
He gestured at the great copper cookers, the maze of tubing, the complex system of troughs that delivered malted grain to the mash tun and then transferred the clarified wort to the huge brew-kettle.