The Collaborative International Dictionary of English v.0.48:

Gush \Gush\ (g[u^]sh), v. i. [imp. & p. p. Gushed (g[u^]sht);
   p. pr. & vb. n. Gushing.] [OE. guschen, cf. Icel. gusa and
   gjsa, also D. gucsen; perh. akin to AS. ge['o]tan to pour, G.
   giessen, Goth. giutan, E. gut. Cf. Found to cast.]
   [1913 Webster]
   1. To issue with violence and rapidity, as a fluid; to rush
      forth as a fluid from confinement; to flow copiously.
      [1913 Webster]

            He smote the rock that the waters gushed out. --Ps
                                                  ixxviii 20.
      [1913 Webster]

            A sea of blood gushed from the gaping wound.
                                                  --Spenser.
      [1913 Webster]

   2. To make a sentimental or untimely exhibition of affection;
      to display enthusiasm in a silly, demonstrative manner.
      [Colloq.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Gushing \Gush"ing\, a.
   1. Rushing forth with violence, as a fluid; flowing
      copiously; as, gushing waters. "Gushing blood." --Milton.
      [1913 Webster]

   2. Emitting copiously, as tears or words; weakly and
      unreservedly demonstrative in matters of affection;
      sentimental. [Colloq.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

gushing
    adj 1: flowing profusely; "a gushing hydrant"; "pouring flood
           waters" [syn: gushing, pouring]
    2: uttered with unrestrained enthusiasm; "a novel told in burbly
       panting tones" [syn: burbling, burbly, effusive,
       gushing]
    3: extravagantly demonstrative; "insincere and effusive
       demonstrations of sentimental friendship"; "a large gushing
       female"; "write unrestrained and gushy poetry" [syn:
       effusive, gushing(a), gushy]

Moby Thesaurus II by Grady Ward, 1.0:

146 Moby Thesaurus words for "gushing":
   abundance, abundant, adulatory, affluent, amplitude, bathetic,
   beery, bland, blandishing, blarneying, buttery, cajoling,
   cloud of words, cloying, complimentary, confluent, copious,
   copiousness, coursing, courtierly, courtly, decurrent, defluent,
   diffluent, diffuse, diffuseness, diffusion, diffusive,
   diffusiveness, effusion, effusive, effusiveness, extravagance,
   extravagant, exuberance, exuberant, fair-spoken, fawning, fecund,
   fecundity, fertility, fine-spoken, flattering, flowing, fluency,
   fluent, fluxional, fluxive, formless, formlessness, fulsome, gooey,
   gulfy, gush, gushy, honey-mouthed, honey-tongued, honeyed,
   insincere, insinuating, logorrhea, macrology, maudlin, mawkish,
   mazy, mealymouthed, meandering, mushy, namby-pamby, nostalgic,
   nostomanic, obsequious, oily, oily-tongued, outpour, overflow,
   overflowing, oversentimental, oversentimentalized, palilogy,
   pleonasm, pleonastic, pouring, prodigal, prodigality, productive,
   productivity, profluent, profuse, profuseness, profusion,
   profusive, prolific, prolificacy, prolificity, racing, rampancy,
   rankness, redundancy, redundant, reiteration, reiterative,
   reiterativeness, repetition for effect, repetitive, repetitiveness,
   romantic, running, rushing, sappy, sentimental, sentimentalized,
   serpentine, slimy, slobbering, slobbery, sloppy, sluggish, smarmy,
   smooth, smooth-spoken, smooth-tongued, soapy, soft, soft-soaping,
   sticky, streaming, superabundance, superabundant, superfluity,
   superflux, surging, surgy, sycophantic, talkativeness, tautologous,
   tautology, tear-jerking, teary, teeming, teemingness, tidal,
   tirade, unctuous, vortical, wheedling