What is "malleation"

Malleation \Mal`le*a"tion\, n. [LL. malleatio: cf. OF. mall['e]ation.] The act or process of beating into a plate, sheet, or leaf, as a metal; extension by beating.

n. 1 The act or process of beating into a plate, sheet, or leaf, as a metal; extension by beating. 2 A hammering movement of the hands against the thighs, a form of tic.