"everywhere," Old English ofer eall, from ofer "over" (see over) + eall (see all). Sense of "including everything" is from 1894. The noun in the clothing sense (usually plural) of "loose trousers of a strong material worn by cowboys, etc." is from 1782. Specific sense "loose fitting canvas trousers with a bib and strap top" (originally worn by workmen over other clothes to protect them from wet, dirt, etc.) is attested from 1897.