Association/əˌsəʊsiˈeɪʃn/ Definition 1 of 5Pro Tip 1/3Purpose Driven Associations are formed for specific purposes; they're not just casual groups. She founded an association for renewable energy advocacy. Pro Tip 2/3Shared Interests Members usually share common goals or hobbies which drive the association's activities. He's in an association for bird watchers. Pro Tip 3/3Formal Structure An association often has a structured organization with roles like president or treasurer. She was elected treasurer of the association.