association

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act of associating or the state of being associated.
2. n. An organized body of people who have an interest, activity, or purpose in common; a society.
3. n. A mental connection or relation between thoughts, feelings, ideas, or sensations.
4. n. A remembered or imagined feeling, emotion, idea, or sensation linked to a person, object, or idea.
5. n. Chemistry Any of various processes of combination, such as hydration, solvation, or complex-ion formation, depending on relatively weak chemical bonding.
6. n. Ecology A large number of organisms in a specific geographic area constituting a community with one or two dominant species.

Century Dictionary and Cyclopedia

1. n. The act of associating or the state of being associated. Connection of persons or things; union.
2. n. A union or connection of ideas. See association of ideas, below.
3. n. An organized union of persons for a common purpose; a body of persons acting together for the promotion of some object of mutual interest or advantage; a partnership, corporation, or society: as, the Association for the Advancement of Science; a political or charitable association.
4. n. In physical chemistry, the union of chemical molecules to form more complex aggregates; especially, the union of the molecules of a vapor to form more complex aggregates when the temperature is reduced nearly to the boiling-point, or when they condense into liquids. Acetic acid at 250° C. consists of molecules weighing sixty times the atom of hydrogen, but at 125° C. about half of the molecules weigh twice as much, which proves that two thirds of its gaseous molecules show association of two normal molecules into one. Amer. Jour. Sci., June, 1904, p. 428.
5. n. In phytogeography, the aggregation of plant individuals initiated by reproduction on the spot of growth, but finally determined by environment. See formation and plant association.
6. n. A local aggregation of plants within a formation characterized more by the species which compose it than by any biological peculiarity.

Wiktionary

1. n. The act of associating.
2. n. The state of being associated; a connection to or an affiliation with something.
3. n. A group of persons associated for a common purpose; an organization; society.

GNU Webster's 1913

1. n. The act of associating, or state of being associated; union; connection, whether of persons of things.
2. n. Mental connection, or that which is mentally linked or associated with a thing.
3. n. Union of persons in a company or society for some particular purpose. Specifically, as among the Congregationalists, a society, consisting of a number of ministers, generally the pastors of neighboring churches, united for promoting the interests of religion and the harmony of the churches.

WordNet 3.0

1. n. a formal organization of people or groups of people
2. n. a social or business relationship
3. n. (ecology) a group of organisms (plants and animals) that live together in a certain geographical region and constitute a community with a few dominant species
4. n. the act of consorting with or joining with others
5. n. the state of being connected together as in memory or imagination
6. n. (chemistry) any process of combination (especially in solution) that depends on relatively weak chemical bonding
7. n. the process of bringing ideas or events together in memory or imagination
8. n. a relation resulting from interaction or dependence