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

Words within markers