Definition of marker

• n. - One who or that which marks.
• n. - One who keeps account of a game played, as of billiards.
• n. - A counter used in card playing and other games.
• n. - The soldier who forms the pilot of a wheeling column, or marks the direction of an alignment.
• n. - An attachment to a sewing machine for marking a line on the fabric by creasing it.