By post-Conquest lawyers explained (perhaps by conjecture based on the etymology) to mean: The fine for taking provisions from a market before the…

A fine or discretionary penalty exacted in accordance with such a document; such fines collectively. See amercement, n. Obsolete.

(apparently) a fine paid by a person who is not a burgess of a town or city in order to be allowed to display goods for sale in his or her window.

A fine formerly exacted from the owners of marsh lands for failure to repair banks, ditches, etc.