The Collaborative International Dictionary of English v.0.48:

Pungent \Pun"gent\, a. [L. pungens, -entis, p. pr. of pungere,
   punctum, to prick. Cf. Compunction, Expunge, Poignant,
   Point, n., Puncheon, Punctilio, Punt, v. t.]
   1. Causing a sharp sensation, as of the taste, smell, or
      feelings; pricking; biting; acrid; as, a pungent spice.
      [1913 Webster]

            Pungent radish biting infant's tongue. --Shenstone.
      [1913 Webster]

            The pungent grains of titillating dust. --Pope.
      [1913 Webster]

   2. Sharply painful; penetrating; poignant; severe; caustic;
      stinging.
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            With pungent pains on every side.     --Swift.
      [1913 Webster]

            His pungent pen played its part in rousing the
            nation.                               --J. R. Green.
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   3. (Bot.) Prickly-pointed; hard and sharp.
      [1913 Webster]

   Syn: Acrid; piercing; sharp; penetrating; acute; keen;
        acrimonious; biting; stinging.
        [1913 Webster]

WordNet (r) 3.0 (2006):

pungent
    adj 1: strong and sharp;"the pungent taste of radishes"; "the
           acrid smell of burning rubber" [syn: pungent, acrid]
    2: capable of wounding; "a barbed compliment"; "a biting
       aphorism"; "pungent satire" [syn: barbed, biting,
       nipping, pungent, mordacious]

Moby Thesaurus II by Grady Ward, 1.0:

153 Moby Thesaurus words for "pungent":
   Attic, acerb, acerbate, acerbic, acescent, acid, acrid,
   acrimonious, acute, afflictive, agonizing, amaroidal, aphoristic,
   aromatic, asperous, astringent, atrocious, axiomatic, barbed,
   biting, bitter, bitter as gall, brilliant, caustic, clever, coarse,
   consuming, crab, crabbed, cramping, crisp, cruel, cutting,
   deafening, distressing, droll, dry, epigrammatic, escharotic,
   exciting, excruciating, facetious, flavorful, formulaic,
   formulistic, funny, gnawing, gnomic, grave, green, griping, hard,
   harrowing, harsh, hot, humorous, humorsome, hurtful, hurting,
   incisive, intense, irritating, jesting, jocose, jocular, joking,
   joky, joshing, keen, keen-witted, lively, loud, mordant,
   nimble-witted, nose-piercing, nose-tickling, oppressive, painful,
   paroxysmal, penetrating, peppery, peppy, pickled, piercing,
   piquant, pithy, platitudinous, poignant, pointed, proverbial,
   provocative, quick-witted, racking, racy, rapier-like, reeking,
   rich, rough, salt, salty, sapid, sarcastic, scathing,
   scintillating, seasoned, sec, sententious, severe, sharp, shooting,
   smart, snappy, sour, sour as vinegar, soured, sourish, sparkling,
   spasmatic, spasmic, spasmodic, spicy, spirited, sprightly,
   stabbing, stern, stimulating, stinging, strong, strong-scented,
   strong-smelling, succinct, suffocating, tangy, tart, tartish,
   tasty, terse, thundering, tormenting, torturous, trenchant,
   uninteresting, unripe, unsweet, unsweetened, upsetting, vinegarish,
   vinegary, vitriolic, vivacious, whimsical, witty, zesty