noun

• The act or fact of communicating anything; transmission.
• (uncountable) The concept or state of exchanging data or information between entities.
• A message; the essential data transferred in an act of communication.
• The body of all data transferred to one or both parties during an act of communication.
• An instance of information transfer; a conversation or discourse.
• A passageway or opening between two locations; connection.
• (anatomy) A connection between two tissues, organs, or cavities.
• (obsolete) Association; company.
• Participation in Holy Communion.
• (rhetoric) A trope by which a speaker assumes that his hearer is a partner in his sentiments, and says "we" instead of "I" or "you".