The Collaborative International Dictionary of English v.0.48:

Poignant \Poign"ant\, a. [F., p. pr. of poindre to sting, fr. L.
   pungere to prick, sting. See Pungent.]
   1. Pricking; piercing; sharp; pungent. "His poignant spear."
      --Spenser. "Poynaunt sauce." --Chaucer.
      [1913 Webster]

   2. Fig.: Pointed; keen; satirical.
      [1913 Webster]

            His wit . . . became more lively and poignant. --Sir
                                                  W. Scott.
      [1913 Webster]

WordNet (r) 3.0 (2006):

poignant
    adj 1: arousing affect; "the homecoming of the released hostages
           was an affecting scene"; "poignant grief cannot endure
           forever"; "his gratitude was simple and touching" [syn:
           affecting, poignant, touching]
    2: keenly distressing to the mind or feelings; "poignant
       anxiety"

Moby Thesaurus II by Grady Ward, 1.0:

162 Moby Thesaurus words for "poignant":
   absorbing, acerbic, acid, acidulous, acrid, acrimonious, acute,
   affecting, afflictive, agitating, agonizing, asperous, astringent,
   atrocious, barbed, biting, bitter, bleak, blue, caustic, cheerless,
   comfortless, corrosive, cramping, cruel, cutting, deep, deep-felt,
   deepgoing, deplorable, depressing, depressive, disastrous,
   discomforting, dismal, dismaying, distressful, distressing,
   disturbing, dolorific, dolorogenic, dolorous, double-edged,
   dramatic, dreary, driving, earnest, edged, effective, emotional,
   escharotic, excruciating, exquisite, extreme, fierce, forceful,
   forcible, gnawing, grave, grievous, griping, gutsy, hard,
   harrowing, harsh, heartfelt, homefelt, hurtful, hurting,
   imperative, impressive, incisive, indelible, intense, irritating,
   joyless, keen, lamentable, lively, melancholy, miserable,
   mordacious, mordant, mournful, moving, nervous, nose-tickling,
   painful, paroxysmal, pathetic, penetrating, peppery, peppy,
   perturbing, pervading, piercing, piquant, piteous, pitiable,
   pitiful, pointed, powerful, profound, punchy, pungent, racking,
   racy, regrettable, rigorous, rough, rueful, sad, saddening,
   sarcastic, sardonic, scathing, sensational, severe, sharp,
   shooting, sincere, sinewed, sinewy, slashing, snappy, sore,
   sorrowful, sour, sparkling, spasmatic, spasmic, spasmodic, spicy,
   spirited, stabbing, stinging, stirring, strident, striking,
   stringent, strong, tart, telling, tormenting, torturous, touching,
   tragic, trenchant, uncomfortable, upsetting, vehement, vigorous,
   violent, virulent, vital, vitriolic, vivacious, vivid, woebegone,
   woeful, wretched, zesty