Costermonger, coster, or costard is a street seller of fruit and vegetables usually from a barrow in London and other British towns. The term is derived from two words - costard (a now extinct medieval variety of large, ribbed eating apple thought to be similar to a Jersey Bellflower apple. It is mentioned, by the name "Poma Costard", in a fruitier's bill for Edward I in 1292. It was said to resemble a person's head which in Norman French was also costard, although the term probably derived from the Latin costa for rib.
And monger (seller)