Why is the ninth month called September?
c.1200, from Anglo-French marchaunt "merchant, shopkeeper" (Old French marcheant, Modern French marchand), from Vulgar Latin *mercatantem (nominative *mercatans) "a buyer," present participle of *mercatare, frequentative of Latin mercari "to trade, traffic, deal in" (see market). Meaning "fellow, chap" is from 1540s; with a specific qualifier, and suggesting someone who deals in it (e.g. speed merchant "one who enjoys fast driving"), from 1914.
c.1400, from merchant (n.) and from Old French marcheant (adj.).
A person who esp indulges or purveys in what is indicated: heat merchant/ speed merchant (1914+)
The Hebrew word so rendered is from a root meaning "to travel about," "to migrate," and hence "a traveller." In the East, in ancient times, merchants travelled about with their merchandise from place to place (Gen. 37:25; Job 6:18), and carried on their trade mainly by bartering (Gen. 37:28; 39:1). After the Hebrews became settled in Palestine they began to engage in commercial pursuits, which gradually expanded (49:13; Deut. 33:18; Judg. 5:17), till in the time of Solomon they are found in the chief marts of the world (1 Kings 9:26; 10:11, 26, 28; 22:48; 2 Chr. 1:16; 9:10, 21). After Solomon's time their trade with foreign nations began to decline. After the Exile it again expanded into wider foreign relations, because now the Jews were scattered in many lands.