co-op

Short definition from Wiktionary

Noun

1. 1
   A unit of a housing cooperative; a purchased apartment where the apartment owners collectively are responsible for maintenance of common areas and upkeep.
2. 2
   Any cooperative, including housing, retail, utility, agricultural, banking or worker cooperatives.
3. 3
   Any shop owned by a cooperative.
4. 4
   A cooperative game, as opposed to a competitive game or deathmatch.
5. 5
   Any of very many shops belonging to the Co-operative Group and its predecessors

Verb

1. 1
   Synonym of cooperate.