Why is a brush called a brush?

A brush is called a brush because of its historical linguistic origin related to the action of brushing or sweeping and the material it was made from. The English word brush comes from Middle English brusche and Old French broche and brosse, meaning a brushwood, twigs, or a bundle of twigs, and also from Vulgar Latin brustia, related to bristles. Originally, brushes were made from bundles of twigs, branches, or animal bristles tied together to sweep or scrub, so the tool was named after its material, which was brushwood or bristly fibers. The verb to brush meaning to sweep, clean with a brush, or touch lightly comes from the same root, describing the action performed with the tool. For vegetation, brush is called brush because it consists of brushwood, small branches, twigs, and shrubby growth that could be gathered to make brooms or brushes, or that resembles bristles. So the tool and the vegetation share the same name because early brushes were literally made from brushwood. Over time, the word expanded to cover any tool with bristles for cleaning, painting, or grooming, and any dense shrubby growth. So it is called brush because of its bristly nature and origin from twigs and brushwood.