an organization of people with a common purpose and having a formal structure.

the act of associating or state of being associated.

friendship; companionship

Their close association did not last long.

connection or combination.

the connection or relation of ideas, feelings, sensations, etc.; correlation of elements of perception, reasoning, or the like.

an idea, image, feeling, etc., suggested by or connected with something other than itself; an accompanying thought, emotion, or the like; an overtone or connotation

My associations with that painting are of springlike days.

Ecology . a group of plants of one or more species living together under uniform environmental conditions and having a uniform and distinctive aspect.

Chemistry . a weak form of chemical bonding involving aggregation of molecules of the same compound.

touch football.

Astronomy . stellar association.