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.

noun

aloneness , antagonism , disunion , isolation , opposition , rivalry , seclusion , separation , solitude , disassociation , division , disconnection

noun

affiliation , alliance , band , bunch , circle , clan , clique , club , coalition , combination , combo , company , confederacy , confederation , congress , cooperative , corporation , crew , crowd , family , federation , fellowship , fraternity , gang , guild , hookup , league , mob , order , organization , outfit , partnership , pool , rat pack , ring , society , sodality , sorority , syndicate , tie-in , tie-up , tribe , troops , troupe , union , zoo , acquaintance , acquaintanceship , agreement , assistance , camaraderie , companionship , comradeship , conjunction , cooperation , familiarity , fraternization , frequenting , friendliness , intimacy , membership , participation , relation , relationship , bond , concomitance , concordance , connotation , correlation , identification , impression , joining , juxtaposition , linkage , linking , lumping together , mixing , mixture , pairing , recollection , remembrance , tie , train of thought , connection , circuit , loop , assemblage , cabal , cartel , coperation , coadjuvancy , collaboration , collusion , confraternity , converse , coop , council , lodge , lyceum , pledge