an object used to indicate a position, place, or route.
they erected a granite marker at the crash site
a felt-tip pen with a broad tip.
On last day of school you attempted to get me disqualified from my business exam by using a marker pen and writing on me
(chiefly in soccer) a player who is assigned to mark a particular opponent.
On one occasion he picked up the ball, spun his marker , played a quick one-two, dashed clear… and put the ball wide.
a person who records the score in a game, especially in snooker or billiards.
He strode in, startling the billiard marker , Thomas Budd, who was about to close the side door.