[syn: acuate, acute, sharp, needlelike]
6.  of critical importance and consequence; 
- Example: "an acute (or critical) lack of research funds"
The Collaborative International Dictionary of English v.0.48:
Acute \A*cute"\, a. [L. acutus, p. p. of acuere to sharpen, fr.
   a root ak to be sharp. Cf. Ague, Cute, Edge.]
   1. Sharp at the end; ending in a sharp point; pointed; --
      opposed to blunt or obtuse; as, an acute angle; an
      acute leaf.
      [1913 Webster]
   2. Having nice discernment; perceiving or using minute
      distinctions; penetrating; clever; shrewd; -- opposed to
      dull or stupid; as, an acute observer; acute remarks,
      or reasoning.
      [1913 Webster]
   3. Having nice or quick sensibility; susceptible to slight
      impressions; acting keenly on the senses; sharp; keen;
      intense; as, a man of acute eyesight, hearing, or feeling;
      acute pain or pleasure.
      [1913 Webster]
   4. High, or shrill, in respect to some other sound; --
      opposed to grave or low; as, an acute tone or accent.
      [1913 Webster]
   5. (Med.) Attended with symptoms of some degree of severity,
      and coming speedily to a crisis; -- opposed to chronic;
      as, an acute disease. AS
      [1913 Webster]
   Acute angle (Geom.), an angle less than a right angle.
      [1913 Webster]
   Syn: Subtile; ingenious; sharp; keen; penetrating; sagacious;
        sharp-witted; shrewd; discerning; discriminating. See
        Subtile.
        [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Acute \A*cute"\, v. t.
   To give an acute sound to; as, he acutes his rising
   inflection too much. [R.] --Walker.
   [1913 Webster]
WordNet (r) 3.0 (2006):
acute
    adj 1: having or experiencing a rapid onset and short but severe
           course; "acute appendicitis"; "the acute phase of the
           illness"; "acute patients" [ant: chronic]
    2: extremely sharp or intense; "acute pain"; "felt acute
       annoyance"; "intense itching and burning" [syn: acute,
       intense]
    3: having or demonstrating ability to recognize or draw fine
       distinctions; "an acute observer of politics and
       politicians"; "incisive comments"; "icy knifelike reasoning";
       "as sharp and incisive as the stroke of a fang"; "penetrating
       insight"; "frequent penetrative observations" [syn: acute,
       discriminating, incisive, keen, knifelike,
       penetrating, penetrative, piercing, sharp]
    4: of an angle; less than 90 degrees [ant: obtuse]
    5: ending in a sharp point [syn: acuate, acute, sharp,
       needlelike]
    6: of critical importance and consequence; "an acute (or
       critical) lack of research funds"
    n 1: a mark (') placed above a vowel to indicate pronunciation
         [syn: acute accent, acute, ague]
Moby Thesaurus II by Grady Ward, 1.0:
284 Moby Thesaurus words for "acute":
   Machiavellian, Machiavellic, absorbing, acanthoid, acanthous,
   accurate, acicular, acrid, active, acuate, aculeate, aculeiform,
   acuminate, afflictive, aggravated, aggressive, agonizing, alert,
   animated, apperceptive, appercipient, arch, argute, artful, astute,
   atrocious, aware, barbed, biting, brisk, cagey, canny, clamorous,
   clever, climacteric, cogent, compelling, cornuted, crafty,
   cramping, creaky, critical, crucial, cruel, crying, cunning,
   cusped, cuspidate, cute, cutting, dangerous, deceitful, deep,
   deep-felt, deep-laid, deepgoing, designing, desperate, diplomatic,
   dire, discerning, discriminating, distressing, double-edged,
   drastic, dynamic, ear-piercing, edged, energetic, enterprising,
   enthusiastic, excessive, excruciating, exigent, exorbitant,
   exquisite, extravagant, extreme, farseeing, farsighted,
   featheredged, feline, fierce, fine, forceful, forcible, foreseeing,
   foresighted, forethoughted, forethoughtful, foxy, full of pep,
   furious, gnawing, go-go, grave, great, griping, guileful, hard,
   harrowing, harsh, hazardous, heartfelt, hearty, high,
   high-pressure, high-priority, hispid, homefelt, horned, horny,
   howling, hurtful, hurting, immoderate, imperative, imperious,
   impetuous, incisive, indelible, ingenious, insidious, insightful,
   insistent, instant, intelligent, intemperate, intense, intensified,
   inventive, keen, keen-edged, keening, kinetic, knifelike, knowing,
   lively, living, longheaded, longsighted, lusty, menacing,
   meticulous, mettlesome, mucronate, narrow, needle-pointed,
   needle-sharp, observant, outrageous, painful, paroxysmal, pawky,
   peaked, peaky, penetrating, peppy, perceptive, percipient,
   perilous, perspicacious, perspicuous, pervading, piercing, piping,
   pivotal, poignant, pointed, politic, precarious, precise, pressing,
   prickly, probing, profound, pronged, provident, pungent,
   quick-witted, racking, razor-edged, ready, reedy, resourceful,
   rigorous, robust, rough, sagacious, scheming, screaky, screeching,
   screechy, sensitive, serious, serpentine, set, severe, shall,
   sharp, sharp-pointed, sharp-sighted, sharp-witted, shifty,
   shooting, shrewd, shrieking, shrieky, shrill, slick, slippery, sly,
   smacking, smooth, snaky, snappy, sneaky, sophistical, spanking,
   spasmatic, spasmic, spasmodic, spiculate, spiked, spiky, spined,
   spinous, spiny, spirited, splitting, squeaking, squeaky, stabbing,
   stealthy, stinging, strategic, strenuous, strong, subtile, subtle,
   sudden, supple, tactical, take-charge, take-over, tapered,
   tapering, thin, threatening, tined, tinny, toothed, tormenting,
   torturous, tough, treble, trenchant, trickish, tricksy, tricky,
   two-edged, ululant, unbated, unconscionable, understanding, urgent,
   vehement, venomous, vibrant, vigorous, violent, virulent,
   vivacious, vivid, vulpine, wailing, wary, whining, whistling, wily,
   wise, zestful, zesty, zippy
V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):
ACUTE
       Airbus Cockpit Universal Thrust Emulator (Airbus, A380)