pedal

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A foot-operated lever used for actuating or controlling a mechanism, as in a loom, sewing machine, piano, or organ.
• noun A similar foot-operated part attached to a crank and used for powering various devices, such as a bicycle.
• noun A pedal point.
• noun A pedal keyboard.
• adjective Of or relating to a pedal.
• adjective Of or relating to a foot or footlike part.
• intransitive verb To use or operate a pedal or pedals.
• intransitive verb To ride a bicycle.
• intransitive verb To operate the pedals of.

from The Century Dictionary.

• To work a pedal; use the pedals, as of a piano, organ, bicycle, etc.
• In geometry, pertaining to the feet of transversals on to the sides of a triangle through a given point and the vertices.
• noun In geometry, a pedal triangle (which see, under triangle).
• Pertaining to or connected with a foot or the feet: as, pedal extremities.
• Technically— Of or pertaining to a foot-like part of the body, as of a mollusk; podial: as, a pedal ganglion.
• Of or pertaining to the pes or hind foot only: opposed to manual.
• Pertaining to the feet of perpendiculars let fall from one point upon tangents to a fixed locus called a basis.
• 4 (ped′ al). In music, relating to a pedal.
• In conchology: Any muscle of the foot or podium of a univalve. The posterior adductor of a bivalve, when there are two. See cuts under Astartidæ and Tridaenidæ.
• noun Any part of a machine or apparatus which is intended to receive and transmit power from the foot of the operator; a treadle: as, the pedals of a bicycle.
• noun In musical instruments, a foot-lever; a metal or wooden key or projecting bar operated by the foot. , ,
• noun Same as organ-point.
• noun A pedal curve or surface, or one of which another is the pedal curve or surface.

from the GNU version of the Collaborative International Dictionary of English.

• noun (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.
• noun (Geom.) A pedal curve or surface.
• adjective Of or pertaining to the foot, or to feet, literally or figuratively; specifically (Zoöl.), pertaining to the foot of a mollusk.
• adjective Of or pertaining to a pedal; having pedals.
• adjective (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.
• adjective (Mus.) the note which is held or sustained through an organ point. See Organ point, under Organ.
• adjective (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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A lever operated by one's foot that is used to control a machine or mechanism, such as a bicycle or piano
• noun medicine a foot or footlike part.
• verb To operate a pedal attached to a wheel in a continuous circular motion.
• verb To operate a bicycle.
• adjective Of or relating to the foot.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a lever that is operated with the foot
• noun a sustained bass note
• adjective of or relating to the feet
• verb operate the pedals on a keyboard instrument
• verb ride a bicycle