1. The act of associating; union; connection of persons.
2. Union of persons in a company; a society formed for transacting or carrying on some business for mutual advantage; a partnership. It is often applied to a union of states or a confederacy.
3. Union of things; apposition, as of particles of matter.
4. Union or connection of ideas. An association of ideas is where two or more ideas constantly or naturally follow each other in the mind, so that one almost infallibly produces the other.
5. An exertion or change of some extreme part of the sensory residing in the muscles or organs of sense, in consequence of some antecedent or attendant fibrous contractions.
6. In ecclesiastical affairs, a society of the clergy, consisting of a number of pastors of neighboring churches, united for promoting the interests of religion and the harmony of the churches.