Webster's Revised Unabridged Dictionary · 1913

Amerce

Amerce (ȧ*mẽrs") , transitive verb

[Old French amercier, from a merci at the mercy of, liable to a punishment. See Mercy.]

1.
To punish by a pecuniary penalty, the amount of which is not fixed by law, but left to the discretion of the court; as, the court amerced the criminal in the sum of one hundred dollars.

The penalty or fine may be expressed without a preposition, or it may be introduced by in, with, or of.

2.
To punish, in general; to mulct.
Millions of spirits for his fault amerced Of Heaven. — Milton
Shall by him be amerced with penance due. — Spenser