■ noun 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.
Word History
Trade wind is first recorded from the mid 17th century, and comes from the obsolete phrase blow trade meaning 'blow steadily in the same direction'. Trade formerly meant 'course, direction' and 'track' before it acquired its modern meanings of 'an occupation' and 'buying and selling'. The importance of the ~s to the transport of goods by sea misled 18th-century etymologists into connecting the word trade with ‘commerce’.