The Collaborative International Dictionary of English v.0.48:
Pedal \Pe"dal\ (p[=e]"dal in def 1; 277), 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 (Zool.), pertaining to the foot
of a mollusk; as, the pedal ganglion.
2. (p[e^]d"al) Of or pertaining to a pedal; having pedals.
Pedal curve or Pedal 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
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.