noun

marker

MAR-ker/ˈmɑːrkər/

Something used to create or display an identifying sign.

A bright marker identifies the corner where two boundary strings meet.

A bright survey stake marks the corner where two taut boundary strings meet on a small patch of ground.

Etymology

markOld Englishto mark, trace boundaries

A marker is something that marks: it makes a position or boundary identifiable. This preserves the old boundary-sign idea in mark; the modern noun may be a separate formation from the early word for a writer.

In context

Whispering Pines Horror9:04

Steel posts, six feet tall, four inches in diameter Painted white with weather-resistant paint Black lettering showing: "OLYMPIC NATIONAL PARK BOUNDARY" and a unique marker number

Rangers Refuse to Explain the Blue Boundary Markers

More examples

She uses a black marker to label each storage box.
Follow the blue markers along the trail.
He moves his marker forward three spaces on the game board.

Forms

marker · markers

mark verb — To make an identifying sign on something.

Similar words

sign: Usually displays words or symbols rather than simply marking position.
pen: Typically has a narrower writing tip than a felt-tip marker.