The Collaborative International Dictionary of English v.0.48:

Confluence \Con"flu*ence\, n. [L. confluentia.]
   1. The act of flowing together; the meeting or junction of
      two or more streams; the place of meeting.
      [1913 Webster]

            New York stood at the confluence of two rivers.
                                                  --Bancroft.
      [1913 Webster]

   2. Any running together of separate streams or currents; the
      act of meeting and crowding in a place; hence, a crowd; a
      concourse; an assemblage.
      [1913 Webster]

            You see this confluence, this great flood of
            vistors.                              --Shak.
      [1913 Webster]

            The confluence . . . of all true joys. --Boyle.
      [1913 Webster]

WordNet (r) 3.0 (2006):

confluence
    n 1: a place where things merge or flow together (especially
         rivers); "Pittsburgh is located at the confluence of the
         Allegheny and Monongahela rivers" [syn: confluence,
         meeting]
    2: a flowing together [syn: confluence, conflux, merging]
    3: a coming together of people [syn: concourse, confluence]

Moby Thesaurus II by Grady Ward, 1.0:

146 Moby Thesaurus words for "confluence":
   accompaniment, accordance, affluence, afflux, affluxion,
   agglomeration, agglutination, aggregation, agreement, alliance,
   approach, articulation, assemblage, assembly, association,
   asymptote, bond, bottleneck, bracketing, cahoots, call-up, canvass,
   census, clustering, co-working, coaction, coincidence,
   collaboration, collection, collectivity, colligation,
   collision course, collocation, collusion, combination,
   combined effort, communication, comparison, concatenation,
   concentralization, concentration, concert, concerted action,
   concomitance, concordance, concourse, concurrence, conflux,
   congeries, conglomeration, congregation, congress, conjugation,
   conjunction, connection, consilience, conspiracy, convergence,
   converging, cooperation, copulation, corralling, correspondence,
   coupling, course, crosscurrent, crossing, current, data-gathering,
   defluxion, downflow, downpour, drift, driftage, flow, flowing,
   fluency, flux, focalization, focus, funnel, gathering, gush,
   hookup, hub, inflow, ingathering, intercommunication, intercourse,
   interlinking, inventory, joinder, joining, jointure, junction,
   juxtaposition, knotting, liaison, linkage, linking, marriage,
   meeting, merger, merging, mill run, millrace, mobilization, muster,
   mutual approach, narrowing gap, onrush, onward course, outflow,
   pairing, parasitism, race, radius, rodeo, roundup, run, rush,
   saprophytism, set, simultaneity, spate, splice, spokes, stream,
   surge, survey, symbiosis, synchronism, synergy, tangent, tide, tie,
   tie-in, tie-up, trend, undercurrent, undertow, unification, union,
   united action, water flow, yoking



U.S. Gazetteer Places (2000):

Confluence, PA -- U.S. borough in Pennsylvania
   Population (2000):    834
   Housing Units (2000): 404
   Land area (2000):     1.596582 sq. miles (4.135129 sq. km)
   Water area (2000):    0.052398 sq. miles (0.135709 sq. km)
   Total area (2000):    1.648980 sq. miles (4.270838 sq. km)
   FIPS code:            15680
   Located within:       Pennsylvania (PA), FIPS 42
   Location:             39.809997 N, 79.356692 W
   ZIP Codes (1990):
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Confluence, PA
    Confluence