fraternization (n.)

• affiliation
• alignment
• alliance
• amalgamation
• association
• coalescence
• coalition
• collaboration
• combination
• companionship
• company
• comradeship
• confederacy
• confederation
• consolidation
• cooperation
• copartnership
• federation
• fellowship
• fraternity
• freemasonry
• fusion
• hookup
• inclusion
• incorporation
• integration
• league
• membership
• merger
• participation
• partnership
• quislingism
• sedition
• sharing
• society
• sodality
• sorority
• tie-in
• tie-up
• treason
• unification
• union