The Collaborative International Dictionary of English v.0.48:

outpouring \out"pour`ing\, n.
   An unrestrained expression (of emotion, feeling); as, an
   outpouring of grief over the death of Princess Diana.
   [PJC]

WordNet (r) 3.0 (2006):

outpouring
    n 1: a natural flow of ground water [syn: spring, fountain,
         outflow, outpouring, natural spring]
    2: a sudden rapid flow (as of water); "he heard the flush of a
       toilet"; "there was a little gush of blood"; "she attacked
       him with an outpouring of words" [syn: flush, gush,
       outpouring]
    3: the pouring forth of a fluid [syn: discharge, outpouring,
       run]
    4: the rapid and continuous delivery of linguistic communication
       (spoken or written); "a barrage of questions"; "a bombardment
       of mail complaining about his mistake" [syn: barrage,
       bombardment, outpouring, onslaught]
    5: a large flow [syn: flood, overflow, outpouring]

Moby Thesaurus II by Grady Ward, 1.0:

101 Moby Thesaurus words for "outpouring":
   Niagara, abundance, affluence, ample sufficiency, ampleness,
   amplitude, avalanche, bonanza, bountifulness, bountiousness,
   bumper crop, cascade, cataract, copiousness, debouchment,
   defluxion, deluge, discharge, drain, drainage, effluence, effluent,
   efflux, effluxion, effused, effusion, effusive, emanation,
   exhalation, exhaust, extravagance, extravasated, exuberance,
   fertility, flood, flow, flowoff, foison, full measure, fullness,
   generosity, generousness, great abundance, great plenty, gush,
   gushing, landslide, lavishness, liberality, liberalness, lots,
   luxuriance, maximum, more than enough, much, myriad, myriads,
   numerousness, opulence, opulency, outbound, outburst, outfall,
   outflow, outflowing, outgoing, outpour, outrush, outward-bound,
   overflow, plenitude, plenteousness, plentifulness, plenty,
   prevalence, prodigality, productiveness, profuseness, profusion,
   quantities, repleteness, repletion, rich harvest, rich vein,
   richness, riot, riotousness, runoff, scads, shower, spate,
   spouting, spurt, stream, substantiality, substantialness,
   superabundance, teemingness, tide, torrent, wealth