Emily Dickinson Lexicon

A-MERCE', v.t. [amers'; A verb formed from a for on or at, and Fr. merci, mercy, or from L. merces, reward.]

1. To inflict a penalty at mercy; to punish by a pecuniary penalty, the amount of which is not fixed by law, but left to the discretion or mercy of the court; as, the court amerced the criminal in the sum of one hundred dollars.
2. To inflict a pecuniary penalty; to punish in general. Milton uses of after amerce: "Obvious of spirits amerced of heaven;" but this use seems to be a poetic license.