Pedal

The part of a bicycle, motorcycle, piano or any other mechanic (or sometimes electronic) device you put your foot on. Pedals usually work as levers of some sort. On a bicycle, a pedal is connected to a crank that creates rotary motion which is transferred to the rear wheel by a chain. On a motorcycle, pedals are used for breaking, operating the clutch and shifting the gears. In an instrument like a piano, the pedals have different kinds of functions like sustain (prolongs the note) and soft (softens the tone and volume of the music). Pedals are also used as switches in machinery like lathes, sewing machines and potter's wheels.

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 Zool., pertaining to the foot of a mollusk; as, the pedal ganglion.

2. ()

Of or pertaining to a pedal; having pedals.

Pedal curve ∨ 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.

© Webster 1913.

Pe"dal (?), n. [Cf. F. p'edale, 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.

© Webster 1913.