Association (noun)

1. A connection or cooperative link between people, groups, or countries.
2. A group of people organized for a joint purpose, especially a business or professional organization.
3. The connection of ideas, feelings, or sensations in a person's mind.

Origin:

Late middle english (denoting a spiritual or mental connection): from old french assocacion, from latin associatio(n-), from associare 'unite with' (see associate).

Examples:

1. The company has formed a new association with a leading research group.
2. Membership in the local association provides many benefits.
3. The association has grown rapidly in size and influence.
4. The homeowners association is responsible for maintaining the community's common areas.
5. The association is dedicated to advancing the field of engineering.