pencil

Etymology

From Anglo-Norman and Old French pincil (see the variant pincel, which gave rise to Modern French pinceau (“paintbrush”)), from Latin pēnicillum, diminutive of pēniculus (“brush”), itself a diminutive of pēnis (“tail; penis”). Not related to pen.

noun

1. (now chiefly historical) A paintbrush.
   He requested three things of Sir Joshua Reynolds:—To forgive him thirty pounds which he had borrowed of him; to read the Bible; and never to use his pencil on a Sunday. 1791, James Boswell, Life of Johnson, Oxford, published 2008, page 1390
2. A writing utensil with a graphite (commonly referred to as lead) shaft, usually blended with clay, clad in wood, and sharpened to a taper.
3. (optics) An aggregate or collection of rays of light, especially when diverging from, or converging to, a point.
4. (geometry) 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.
   When, by the pencil becoming oblique to the surface, the vergency produced on the pencil becomes changed, the primary and secondary focal points, V and H, separate […] 1863, The Civil Engineer and Architect's Journal
   Let l and m be two hyperparallel lines. All the transversals to l and m that form congruent corresponding angles with l and m lie in a pencil. 2012, G. E. Martin, The Foundations of Geometry and the Non-Euclidean Plane, page 357
5. (medicine, obsolete, rare) A small medicated bougie.
6. (gambling) Ellipsis of power of the pencil.
   And most important of all, Cully now had 'The Pencil', that most coveted of Las Vegas powers. 1978, Mario Puzo, Fools Die

verb

1. (transitive) To write (something) using a pencil.
   I penciled (BrE: pencilled) a brief reminder in my notebook.
   She had hardly got back when she encountered a piece by Robert Trewe in the new number of her favourite magazine, which must have been written almost immediately before her visit to Solentsea, for it contained the very couplet she had seen pencilled on the wallpaper by the bed, and Mrs. Hooper had declared to be recent. 1888, Thomas Hardy, “An Imaginative Woman”, in Wessex Tales
2. (transitive) To mark with, or as if with, a pencil.
   It pencilled each flower with rich and variegated hues, and threw over its exuberant foliage a vesture of emerald green. 1852, The Ark, and Odd Fellows' Western Magazine