(now chiefly historical) A paintbrush.

A writing utensil with a graphite (commonly referred to as lead) shaft, usually blended with clay, clad in wood, and sharpened to a taper.

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

(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.

(gambling) Ellipsis of power of the pencil.

(transitive) To write (something) using a pencil.

(transitive) To mark with, or as if with, a pencil.