A hawker is a vendor of merchandise that can be easily transported; the term is roughly synonymous with costermonger or peddler. In most places where the term is used, a hawker sells inexpensive goods, handicrafts, or food items. Whether stationary or mobile, hawkers often advertise by loud street cries or chants, and conduct banter with customers, to attract attention and enhance sales.

A costermonger, coster, or costard is a street seller of fruit and vegetables in British towns. The term is derived from the words costard and monger (seller), and later came to be used to describe hawkers in general. Some historians have pointed out that a hierarchy existed within the costermonger class and that while costermongers sold from a handcart or animal-drawn cart, mere hawkers carried their wares in a basket.