The Collaborative International Dictionary of English v.0.48:

Congeries \Con*ge"ri*es\, n. sing. & pl. [L., fr. congerere. See
   Congest.]
   A collection of particles or bodies into one mass; a heap; an
   aggregation.
   [1913 Webster]

WordNet (r) 3.0 (2006):

congeries
    n 1: a sum total of many heterogenous things taken together
         [syn: aggregate, congeries, conglomeration]

Moby Thesaurus II by Grady Ward, 1.0:

115 Moby Thesaurus words for "congeries":
   Anschluss, accumulation, acervation, addition, affiliation,
   agglomerate, agglomeration, agglutination, aggregate, aggregation,
   agreement, alliance, amalgamation, amassment, articulation,
   assemblage, assembly, assimilation, association, blend, blending,
   bond, bracketing, cabal, cartel, centralization, chunk, clustering,
   coalescence, coalition, collection, combination, combine, combo,
   communication, company, composition, concatenation, concourse,
   concurrence, confederacy, confederation, confluence, conglobation,
   conglomerate, conglomeration, congregation, conjugation,
   conjunction, connection, consolidation, conspiracy, convergence,
   copulation, coupling, cumulation, ecumenism, embodiment,
   encompassment, enosis, federalization, federation, fusion,
   gathering, glomeration, gob, group, hookup, hunk, inclusion,
   incorporation, integration, intercommunication, intercourse,
   interlinking, joinder, joining, jointure, junction, junta,
   knotting, league, liaison, linkage, linking, lump, marriage, mass,
   meeting, meld, melding, merger, merging, muster, package,
   package deal, pairing, ruck, snowball, solidification, splice,
   stockpile, symbiosis, syncretism, syndication, syneresis,
   synthesis, tie, tie-in, tie-up, unification, union, wad, wedding,
   yoking