1723, a Kentish word of unknown origin. Originally a piece of iron fitted to a plow for scraping soil; meaning "thin slip of wood to fill up a space or raise a level" is from 1860.
"to wedge up a surface by means of a shim," 1877, from shim (n.). Related: Shimmed; shimming.
A person not appreciative of rock and roll; clyde (1950s+ Rock and roll)