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[L. associare, to ally with]

1. The act of joining or uniting; coordination with another idea or structure; a relationship. In psychiatry, association refers in particular to the relationship of conscious and unconscious ideas or feelings.
2. In genetics, the occurrence of two characteristics at a frequency greater than would be predicted by chance.
3. In clinical epidemiology, the relationship of two events, without evidence of a cause-and-effect relationship. For instance, although malaria occurs in tropical climates, the actual cause is Plasmodium, the malaria parasite, and not environmental heat or stagnant air.

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