means A major road designed for fast, long-distance traffic, with multiple lanes, no crossroads, and restricted access for high-speed driving.

from A straightforward British compound: 'motor' (the car, from Latin 'motor,' a mover) plus 'way' (a road or path, old Germanic stock, related to 'wend' and 'weigh'). It arrived in the 20th century as Britain built its first high-speed roads — where Americans say 'highway' or 'freeway,' Britons named theirs after the motors that would race along them.