Source : Webster's Revised Unabridged Dictionary (1913)

Pedal \Pe"dal\, a. [L. pedalis, fr. pes, pedis, foot. See
   {Foot}, and cf. {Pew}.]
   1. Of or pertaining to the foot, or to feet, literally or
      figuratively; specifically (Zo["o]l.), pertaining to the
      foot of a mollusk; as, the pedal ganglion.

   2. Of or pertaining to a pedal; having pedals.

   {Pedal curve} or {surface} (Geom.), the curve or surface
      which is the locus of the feet of perpendiculars let fall
      from a fixed point upon the straight lines tangent to a
      given curve, or upon the planes tangent to a given
      surface.

   {Pedal note} (Mus.), the note which is held or sustained
      through an organ point. See {Organ point}, under {Organ}.
      

   {Pedal organ} (Mus.), an organ which has pedals or a range of
      keys moved by the feet; that portion of a full organ which
      is played with the feet.

Pedal \Pe"dal\, n. [Cf. F. p['e]dale, It. pedale. See {Pedal},
   a.]
   1. (Mech.) A lever or key acted on by the foot, as in the
      pianoforte to raise the dampers, or in the organ to open
      and close certain pipes; a treadle, as in a lathe or a
      bicycle.

   2. (Geom.) A pedal curve or surface.

Source : WordNet®

pedal
     adj : of or relating to the feet; "the word for a pedal extremity
           is `foot'"
     [also: {pedalling}, {pedalled}]

pedal
     n 1: a sustained bass note [syn: {pedal point}]
     2: a lever that is operated with the foot [syn: {treadle}, {foot
        pedal}, {foot lever}]
     [also: {pedalling}, {pedalled}]

pedal
     v 1: ride a bicycle [syn: {bicycle}, {cycle}, {bike}, {wheel}]
     2: operate the pedals on a keyboard instrument
     [also: {pedalling}, {pedalled}]