a combination or alliance, esp. a temporary one between persons, factions, states, etc.

a union into one body or mass; fusion.

noun

disassociation

noun

affiliation , alliance , amalgam , amalgamation , anschluss , bloc , coadunation , combination , combine , compact , confederacy , confederation , conjunction , consolidation , conspiracy , faction , federation , fusion , integration , league , melding , mergence , merger , merging , party , ring , unification , union , cartel , organization , unity , association , syndicate , trust