as·so·ci·a·tion 
(ə-sō′sē-āshən, -shē-)
(ə-sō′sē-āshən, -shē-)n.
1. The act of associating or being connected with: My parents disapproved of my association with my friends from across town.
2. An organized body of people who have an interest, activity, or purpose in common; a society.
3.
a. A mental connection or relation between thoughts, feelings, ideas, or sensations: My therapist helped me examine my association of food with comfort.
b. The act of expressing a link or connection between two things: "The media's association of visa overstayers with illegality is so strong and common as to shape public attitudes towards them" (Junya Morooka).
4. A correlation or causal connection: There is a definite association of exercise with improved health.
5. Chemistry Any of various processes of combination, such as hydration, solvation, or complex-ion formation, depending on relatively weak chemical bonding.
6. Ecology A large number of organisms in a specific geographic area constituting a community with one or two dominant species.
as·so′ci·ation·al adj.