Source : Webster's Revised Unabridged Dictionary (1913)

Petiole \Pet"i*ole\, n. [F. p['e]tiole, fr. L. petiolus a little
   foot, a fruit stalk; cf. pes, pedis, a foot.]
   1. (Bot.) A leafstalk; the footstalk of a leaf, connecting
      the blade with the stem. See Illust. of {Leaf}.

   2. (Zo["o]l.) A stalk or peduncle.

Source : WordNet®

petiole
     n : the slender stem that supports the blade of a leaf [syn: {leafstalk}]