Source : Webster's Revised Unabridged Dictionary (1913)

Touch-me-not \Touch"-me-not`\, n. (Bot.)
   (a) See {Impatiens}.
   (b) Squirting cucumber. See under {Cucumber}.

Source : WordNet®

touch-me-not
     n 1: North American annual plant with usually yellow or orange
          flowers; grows chiefly on wet rather acid soil [syn: {jewelweed},
           {lady's earrings}, {orange balsam}, {celandine}, {Impatiens
          capensis}]
     2: Mediterranean vine having oblong fruit that when ripe expels
        its seeds and juice violently when touched [syn: {squirting
        cucumber}, {exploding cucumber}, {Ecballium elaterium}]
     3: prostrate or semi-erect subshrub of tropical America, and
        Australia; heavily armed with recurved thorns and having
        sensitive soft gray-green leaflets that fold and droop at
        night or when touched or cooled [syn: {sensitive plant}, {shame
        plant}, {live-and-die}, {humble plant}, {action plant}, {Mimosa
        pudica}]