What is "pencil"

Pencil \Pen"cil\, v. t. [imp. & p. p. Penciledor Pencilled; p. pr. & vb. n. Penciling or Pencilling.] To write or mark with a pencil; to paint or to draw.
--Cowper.

Where nature pencils butterflies on flowers.
--Harte.

Pencil \Pen"cil\, n. [OF. pincel, F. pinceau, L. penicillum, penicillus, equiv. to peniculus, dim. of penis a tail. Cf. Penicil.]

1. A small, fine brush of hair or bristles used by painters for laying on colors.

   With subtile pencil depainted was this storie.
   --Chaucer.

2. A slender cylinder or strip of black lead, colored chalk, slate etc., or such a cylinder or strip inserted in a small wooden rod intended to be pointed, or in a case, which forms a handle, -- used for drawing or writing. See Graphite.

3. Hence, figuratively, an artist's ability or peculiar manner; also, in general, the act or occupation of the artist, descriptive writer, etc.

4. (Opt.) An aggregate or collection of rays of light, especially when diverging from, or converging to, a point.

5. (Geom.) A number of lines that intersect in one point, the point of intersection being called the pencil point.

6. (Med.) A small medicated bougie.

   Pencil case, a holder for pencil lead.

   Pencil flower (Bot.), an American perennial leguminous herb ( Stylosanthes elatior).

   Pencil lead, a slender rod of black lead, or the like, adapted for insertion in a holder.

early 14c., "an artist's fine brush of camel hair," from Old French pincel "artist's paintbrush" (13c., Modern French pinceau), from Latin penicillus "painter's brush, hair-pencil," literally "little tail," diminutive of peniculus "brush," itself a diminutive of penis "tail" (see penis). Small brushes formerly were used for writing before modern lead or chalk pencils; meaning "graphite writing implement" apparently evolved late 16c. Derogatory slang pencil-pusher "office worker" is from 1881; pencil neck "weak person" first recorded 1973.

1530s, "to mark or sketch with a pencil-brush," from pencil (n.). In reference to lead pencils from 1760s. Related: Penciled; penciling. To pencil (something) in "arrange tentatively" is attested from 1942.

n. 1 (context obsolete English) A paintbrush. 2 Writing utensil that uses graphite (commonly referred to as lead). Regular pencils usually have a graphite shaft surrounded by wood. Also available in a mechanical version where the graphite length can be adjusted and sharpening is not needed. 3 (context geometry English) A family of geometric objects with a common property, such as the set of lines that pass through a given point in a projective plane. 4 (context optics English) An aggregate or collection of rays of light, especially when diverging from, or converging to, a point. 5 (context medicine archaic English) A small medicated bougie. vb. to write something using a pencil

1. n. a thin cylindrical pointed writing implement; a rod of marking substance encased in wood

2. graphite (or a similar substance) used in such a way as to be a medium of communication; "the words were scribbled in pencil"; "this artist's favorite medium is pencil"

3. a figure formed by a set of straight lines or light rays meeting at a point

4. a cosmetic in a long thin stick; designed to be applied to a particular part of the face; "an eyebrow pencil"

5. [also: pencilling, pencilled]

1. v. write, draw, or trace with a pencil; "he penciled a figure"

2. [also: pencilling, pencilled]

A pencil is a writing implement or art medium constructed of a narrow, solid pigment core inside a protective casing which prevents the core from being broken or leaving marks on the user’s hand during use.

Pencils create marks by physical abrasion, leaving behind a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which instead disperse a trail of liquid or gel ink that stains the light colour of the paper.

Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased. Graphite pencils are used for both writing and drawing and result in durable markings: though writing is easily removable with an eraser, it is otherwise resistant to moisture, most chemicals, ultraviolet radiation, and natural aging. Other types of pencil core are less widely used, such as charcoal pencils, which are mainly used by artists for drawing and sketching. Coloured pencils are sometimes used by teachers or editors to correct submitted texts, but are typically regarded as art supplies, especially those with waxy core binders that tend to smear on paper instead of erasing. Grease pencils have a softer, crayon-like waxy core that can leave marks on smooth surfaces such as glass or porcelain.

The most common type of pencil casing is of thin wood, usually hexagonal in section but sometimes cylindrical, permanently bonded to the core. Similar permanent casings may be constructed of other materials such as plastic or paper. To use the pencil, the casing must be carved or peeled off to expose the working end of the core as a sharp point. Mechanical pencils have more elaborate casings which support mobile pieces of pigment core that can be extended or retracted through the casing tip as needed.

A pencil is a handheld instrument used to write and draw, usually on paper.

Pencil may also refer to:

• paintbrush, as pencil was a name for this brushes now obsolete
• Pencil (optics), a beam of radiant energy in the form of a narrow cone or cylinder
• Pencil (mathematics), a family of geometric objects
• Matrix pencil, a pair of matrices used in a generalized eigenvalue problem
• Pencil2D, an open-source drawing and animation app
• Pencil (film), an upcoming Tamil film
• Apple Pencil, a stylus device released by Apple Inc.

A pencil in projective geometry is a family of geometric objects with a common property, for example the set of lines that pass through a given point in a projective plane.

More generally, a pencil is the special case of a linear system of divisors in which the parameter space is a projective line. Typical pencils of curves in the projective plane, for example, are written as

where

are plane curves.

A pencil of planes, the family of planes through a given straight line, is sometimes referred to as a fan or a sheaf.

In optics, a pencil or pencil of rays is a geometric construct used to describe a beam or portion of a beam of electromagnetic radiation or charged particles, typically in the form of a narrow cone or cylinder.

Antennas which strongly bundle in azimuth and elevation are often described as "pencil-beam" antennas. For example a phased array antenna can send out a beam that is extremely thin. Such antennas are used for tracking radar. See Beamforming for further details.

In optics, the focusing action of a lens is often described in terms of pencils of rays. In addition to conical and cylindrical pencils, optics deals with astigmatic pencils as well.

In electron optics, scanning electron microscopes use narrow pencil beams to achieve a deep depth of field.

Ionizing radiation used in radiation therapy, whether photons or charged particles, such as proton therapy and electron therapy machines, is sometimes delivered through the use of pencil beam scanning.

Pencil is a 2016 Indian Tamil thriller film written and directed by debutant Mani Nagaraj and produced by S. P. Ragavesh. The film features G. V. Prakash Kumar and Sri Divya in the lead roles, with the former also composing the film's music. The film was released on 13 May 2016.