as·so·ci·a·tion (ə-sō′sē-āshən, -shē-)
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.
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.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.