Retail, to sell goods in small parcels and not in gross. For the purpose of the Licensing Acts, retail of spirits is a sale of less than two gallons (Spirits Act, 1880, s. 104), of wine, of less than two gallons, or one dozen quart bottles (Refreshment Houses Act, 1860, s. 4), and of beer or cider, of less than four gallons and a half. [(English) Beer-house Act, 1834, s. 19]
The sale of goods or commodities to ultimate consumers, as opposed to the sale for further distribution or processing, Black's Law Dictionary, 7th Edn., p. 1317