The Collaborative International Dictionary of English v.0.48:

Emergent \E*mer"gent\, a. [L. emergens, p. pr. of emergere.]
   1. Rising or emerging out of a fluid or anything that covers
      or conceals; issuing; coming to light.
      [1913 Webster]

            The mountains huge appear emergent.   --Milton.
      [1913 Webster]

   2. Suddenly appearing; arising unexpectedly; calling for
      prompt action; urgent.
      [1913 Webster]

            Protection granted in emergent danger. --Burke.
      [1913 Webster]

   Emergent year (Chron.), the epoch or date from which any
      people begin to compute their time or dates; as, the
      emergent year of Christendom is that of the birth of
      Christ; the emergent year of the United States is that of
      the declaration of their independence. -- E*mer"gent*ly,
      adv. -- E*mer"gent*ness, n. [R.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

emergent
    adj 1: occurring unexpectedly and requiring urgent action;
           "emergent repair of an aorta"
    2: coming into existence; "an emergent republic" [syn:
       emergent, emerging]

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "emergent":
   approaching, arising, charged, climacteric, coming, critical,
   crucial, decisive, desired, destinal, destined, determined,
   emanating, emanative, emanent, emerging, eventual, exigent,
   extrapolated, fatal, fated, fatidic, forthcoming, future,
   futuristic, hereafter, hoped-for, imminent, issuing, kairotic,
   later, loaded, nearing, pivotal, planned, plotted, predicted,
   pregnant, probable, projected, prophesied, prospective, surfacing,
   to come, to-be, transeunt, transient, ultimate