·noun One who or that which marks.
II. Marker ·noun A counter used in card playing and other games.
III. Marker ·noun One who keeps account of a game played, as of billiards.
IV. Marker ·noun An attachment to a sewing machine for marking a line on the fabric by creasing it.
V. Marker ·noun The soldier who forms the pilot of a wheeling column, or marks the direction of an Alignment.