association (n.) Look up association at Dictionary.com
1530s, "action of coming together," from Medieval Latin associationem (nominative associatio), noun of action from past participle stem of associare (see associate). Meaning "a body of persons with a common purpose" is from 1650s. Meaning "mental connection" is from 1680s; that of "quality or thing called to mind by something else" is from 1810.