- trade wind
[trade wind 词源字典] - "A wind blowing steadily towards the equator from the north-east in the northern hemisphere or the south-east in the southern hemisphere, especially at sea. Two belts of trade winds encircle the earth, blowing from the tropical high-pressure belts to the low-pressure zone at the equator", Mid 17th century: from the phrase blow trade 'blow steadily in the same direction'. Because of the importance of these winds to navigation, 18th-century etymologists were led erroneously to connect the word trade with ‘commerce’.[trade wind etymology, trade wind origin, 英语词源]
