The Collaborative International Dictionary of English v.0.48:

Immediate \Im*me"di*ate\, a. [F. imm['e]diat. See In- not, and
   Mediate.]
   1. Not separated in respect to place by anything intervening;
      proximate; close; as, immediate contact.
      [1913 Webster]

            You are the most immediate to our throne. --Shak.
      [1913 Webster]

   2. Not deferred by an interval of time; present; instant.
      "Assemble we immediate council." --Shak.
      [1913 Webster]

            Death . . . not yet inflicted, as he feared,
            By some immediate stroke.             --Milton.
      [1913 Webster]

   3. Acting with nothing interposed or between, or without the
      intervention of another object as a cause, means, or
      agency; acting, perceived, or produced, directly; as, an
      immediate cause.
      [1913 Webster]

            The immediate knowledge of the past is therefore
            impossible.                           --Sir. W.
                                                  Hamilton.
      [1913 Webster]

   Immediate amputation (Surg.), an amputation performed
      within the first few hours after an injury, and before the
      the effects of the shock have passed away.

   Syn: Proximate; close; direct; next.
        [1913 Webster]

WordNet (r) 3.0 (2006):

immediate
    adj 1: of the present time and place; "the immediate revisions"
    2: very close or connected in space or time; "contiguous
       events"; "immediate contact"; "the immediate vicinity"; "the
       immediate past" [syn: contiguous, immediate]
    3: having no intervening medium; "an immediate influence" [ant:
       mediate]
    4: immediately before or after as in a chain of cause and
       effect; "the immediate result"; "the immediate cause of the
       trouble"
    5: performed with little or no delay; "an immediate reply to my
       letter"; "a prompt reply"; "was quick to respond"; "a
       straightaway denial" [syn: immediate, prompt, quick,
       straightaway]

Moby Thesaurus II by Grady Ward, 1.0:

198 Moby Thesaurus words for "immediate":
   about to be, abrupt, accessible, actual, adjacent, adjoining,
   alert, already in sight, approaching, apt, articulated, as is,
   at hand, attendant, automatic, available, being, bordering,
   brewing, catenated, ceaseless, close, close at hand, closest,
   coming, concatenated, connected, connecting, constant,
   contemporaneous, contemporary, conterminous, contiguous, continual,
   continued, continuing, continuous, coterminous, current, cursory,
   cyclical, decisive, direct, end to end, endless, endways, endwise,
   existent, existing, expeditious, extant, face to face, featureless,
   festinate, feverish, firsthand, flying, forthcoming, fresh,
   furious, future, gapless, gathering, going to happen, hair-trigger,
   hasty, hurried, immanent, imminent, impendent, impending,
   in danger imminent, in prospect, in reserve, in store,
   in the cards, in the offing, in the wind, in view, incessant,
   indwelling, inherent, instant, instantaneous, instinctive,
   interminable, irreversible, joined, jointless, juxtaposed,
   juxtapositional, juxtapositive, last-minute, latest,
   lightning-like, linked, looming, lowering, lurking, menacing,
   modern, momentaneous, momentary, monotonous, near, near at hand,
   nearby, nearest, nearing, nearmost, neighbor, neighboring,
   never-ending, new, next, nigh, nighest, nonstop, on board, on deck,
   on hand, on the horizon, on the spot, one-way, overhanging,
   passing, perennial, periodic, preparing, present, present-age,
   present-day, present-time, pressing, presto, primary, prompt,
   proximate, punctual, quick, quick as lightning, quick as thought,
   ready, recurrent, reflex, repetitive, round-the-clock, running,
   seamless, serried, slap-bang, slapdash, smooth, snap, speedy,
   spontaneous, stable, steady, straight, straightaway,
   straightforward, straightway, sudden, summary, superficial, swift,
   that be, that is, that will be, threatening, to come, topical,
   twenty-four-hour, unbroken, unceasing, undeviating,
   undifferentiated, unending, unhesitating, unidirectional, uniform,
   unintermitted, unintermittent, unintermitting, uninterrupted,
   unrelieved, unremitting, unstopped, unswerving, unthinking,
   up-to-date, up-to-the-minute, upcoming, urgent, waiting,
   within call, within reach, within sight