Old English mangere "merchant, trader, broker," from mangian "to traffic, trade," from Proto-Germanic *mangojan (cognates: Old Saxon mangon, Old Norse mangari "monger, higgler"), from Latin mango (genitive mangonis) "dealer, trader, slave-dealer," related to mangonium "displaying of wares." Not in Watkins, but Buck (with Tucker) describes it as "one who adorns his wares to give them an appearance of greater value" and writes it is probably a loan-word based on Greek manganon "means of charming or bewitching." Used in comb. form in English since at least 12c.; since 16c. chiefly with overtones of petty and disreputable.

1928, from monger, n.. Not considered to be from Old English mangian. Related: Mongered; mongering (1846).