Moby Thesaurus II by Grady Ward, 1.0:

114 Moby Thesaurus words for "hookup":
   Anschluss, addition, affiliation, agglomeration, agglutination,
   aggregation, agreement, alignment, alliance, amalgamation,
   articulation, assimilation, association, blend, blending, bond,
   bracketing, cabal, cahoots, cartel, centralization, circuit,
   clustering, coadunation, coalescence, coalition,
   coast-to-coast hookup, colleagueship, collegialism, collegiality,
   combination, combine, combo, communication, composition,
   comradeship, concatenation, concourse, concurrence, confederacy,
   confederation, confluence, confraternity, congeries,
   conglomeration, conjugation, conjunction, connection,
   consolidation, conspiracy, convergence, copartnership, copartnery,
   copulation, coupling, ecumenism, embodiment, encompassment, enosis,
   federalization, federation, fellowship, fraternalism, fraternity,
   fraternization, freemasonry, fusion, gathering, inclusion,
   incorporation, integration, intercommunication, intercourse,
   interlinking, joinder, joining, jointure, junction, junta,
   knotting, league, liaison, linkage, linking, marriage, meeting,
   meld, melding, merger, merging, net, network, package,
   package deal, pairing, partnership, radio links, sodality,
   solidification, sorority, splice, symbiosis, syncretism,
   syndication, syneresis, synthesis, tie, tie-in, tie-up,
   togetherness, unification, union, wedding, yoking