TRA'DE-WIND, noun [trade and wind. A wind that favors trade. A trade wind is a wind that blows constantly in the same direction, or a wind that blows for a number of months in one direction, and then changing, blows as long in the opposite direction. These winds in the East Indies are called monsoons, which are periodical. On the Atlantic, within the tropics, the trade winds blow constantly from the eastward to the westward.