Late 16th century. Apparently either from prime + gilt, or from either Middle Low German prīmegelt, prīmgelt, or Dutch †priemgelt (Middle Dutch priemgelt), both in sense ‘money paid to the captain or crew of a ship for taking care of the cargo’, also ‘bonus or gratuity paid to the captain or crew of a ship’, and both from a first element of uncertain origin + respectively Middle Low German gelt and Middle Dutch gelt ‘money’.