Source : Webster's Revised Unabridged Dictionary (1913)

Mandrake \Man"drake\, n. [AS. mandragora, L. mandragoras, fr.
   Gr. ?: cf. F. mandragore.]
   1. (Bot.) A low plant ({Mandragora officinarum}) of the
      Nightshade family, having a fleshy root, often forked, and
      supposed to resemble a man. It was therefore supposed to
      have animal life, and to cry out when pulled up. All parts
      of the plant are strongly narcotic. It is found in the
      Mediterranean region.

            And shrieks like mandrakes, torn out of the earth,
            That living mortals, hearing them, run mad. --Shak.

   Note: The mandrake of Scripture was perhaps the same plant,
         but proof is wanting.

   2. (Bot.) The May apple ({Podophyllum peltatum}). See {May
      apple} under {May}, and {Podophyllum}. [U.S.]

Source : WordNet®

mandrake
     n 1: the root of the mandrake plant; used medicinally or as a
          narcotic [syn: {mandrake root}]
     2: a plant of southern Europe and North Africa having purple
        flowers, yellow fruits and a forked root formerly thought
        to have magical powers [syn: {devil's apples}, {Mandragora
        officinarum}]