noun
Etymology: trade (IV)
: a wind blowing almost constantly in one direction ; especially : a wind that blows almost continually toward the equator from the northeast in the belt between the northern horse latitudes and the doldrums and from the southeast in the belt between the southern horse latitudes and the doldrums and is produced as a result of the rotation of the earth and movement of the air toward the equatorial regions during circulation between the warmer and colder portions of the earth — called also trade ; compare antitrades , monsoon