The Collaborative International Dictionary of English v.0.48:

Imminent \Im"mi*nent\, a. [L. imminens, p. pr. of imminere to
   project; pref. im- in + minere (in comp.) to jut, project.
   See Eminent.]
   1. Threatening to occur immediately; near at hand; impending;
      -- said especially of misfortune or peril. "In danger
      imminent." --Spenser.
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   2. Full of danger; threatening; menacing; perilous.
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            Hairbreadth scapes i' the imminent deadly breach.
                                                  --Shak.
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   3. (With upon) Bent upon; attentive to. [R.]
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            Their eyes ever imminent upon worldly matters.
                                                  --Milton.

   Syn: Impending; threatening; near; at hand.

   Usage: Imminent, Impending, Threatening. Imminent is
          the strongest: it denotes that something is ready to
          fall or happen on the instant; as, in imminent danger
          of one's life. Impending denotes that something hangs
          suspended over us, and may so remain indefinitely; as,
          the impending evils of war. Threatening supposes some
          danger in prospect, but more remote; as, threatening
          indications for the future.
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                Three times to-day
                You have defended me from imminent death.
                                                  --Shak.
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                No story I unfold of public woes,
                Nor bear advices of impending foes. --Pope.
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                Fierce faces threatening war.     --Milton.
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WordNet (r) 3.0 (2006):

imminent
    adj 1: close in time; about to occur; "retribution is at hand";
           "some people believe the day of judgment is close at
           hand"; "in imminent danger"; "his impending retirement"
           [syn: at hand(p), close at hand(p), imminent,
           impendent, impending]