Noah Webster's New International Dictionary of the English Language

1. (n.) State of agreeing; harmony of opinion, statement, action, or character; concurrence; concord; conformity; as, a good agreement subsists among the members of the council.

2. (n.) Concord or correspondence of one word with another in gender, number, case, or person.

3. (n.) A concurrence in an engagement that something shall be done or omitted; an exchange of promises; mutual understanding, arrangement, or stipulation; a contract.

4. (n.) The language, oral or written, embodying reciprocal promises.