from
The Collaborative International Dictionary of English v.0.48
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.
[1913 Webster]
{Mashing tub}, a tub for making the mash in breweries and
distilleries; -- called also {mash tun}, and {mash vat}.
[1913 Webster]