agreement

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The act of agreeing.
• noun Harmony of opinion; accord.
• noun An arrangement between parties, usually resulting from a discussion, regarding a course of action.
• noun A properly executed and legally binding contract.
• noun The writing or document embodying this contract.
• noun Grammar Correspondence in gender, number, case, or person between words.

from The Century Dictionary.

• noun The state of agreeing or of being in accord.
• noun Union of opinions or sentiments; harmony in feeling; absence of dissension: as, a good agreement subsists among the members of the council.
• noun In grammar, correspondence of words in respect of number, gender, etc. See agree, v., I., 8. In logic, capability of being true together: said of terms.
• noun The act of coming to a mutual arrangement; a bargain, contract, covenant, or treaty: as, he made an agreement for the purchase of a house.
• noun Agreeable quality or circumstance; agreeableness: generally in the plural.

from the GNU version of the Collaborative International Dictionary of English.

• noun State of agreeing; harmony of opinion, statement, action, or character; concurrence; concord; conformity.
• noun (Gram.) Concord or correspondence of one word with another in gender, number, case, or person.
• noun A concurrence in an engagement that something shall be done or omitted; an exchange of promises; mutual understanding, arrangement, or stipulation; a contract.
• noun The language, oral or written, embodying reciprocal promises.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun countable An understanding between entities to follow a specific course of conduct.
• noun uncountable A state whereby several parties share a view or opinion; the state of not contradicting one another.
• noun uncountable, law A legally binding contract enforceable in a court of law.
• noun uncountable, linguistics Rules that exist in many languages that force some parts of a sentence to be used or inflected differently depending on certain attributes of other parts.
• noun obsolete, chiefly in plural An agreeable quality.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the statement (oral or written) of an exchange of promises
• noun compatibility of observations
• noun the determination of grammatical inflection on the basis of word relations
• noun the verbal act of agreeing
• noun harmony of people's opinions or actions or characters
• noun the thing arranged or agreed to