1. (Science: botany) Any tree or shrub of the genus salix, including many species, most of which are characterised often used as an emblem of sorrow, desolation, or desertion. A wreath of willow to show my forsaken plight. . Hence, a lover forsaken by, or having lost, the person beloved, is said to wear the willow. And I must wear the willow garland For him that's dead or false to me. (Campbell)
2. A machine in which cotton or wool is opened and cleansed by the action of long spikes projecting from a drum which revolves within a box studded with similar spikes; probably so called from having been originally a cylindrical cage made of willow rods, though some derive the term from winnow, as denoting the winnowing, or cleansing, action of the machine.
Origin: OE. Wilowe, wilwe, AS. Wilig, welig; akin to OD. Wilge, D. Wilg, LG. Wilge. Cf. Willy.