/land"mahrk'/ , n.
1. a prominent or conspicuous object on land that serves as a guide, esp. to ships at sea or to travelers on a road; a distinguishing landscape feature marking a site or location: The post office served as a landmark for locating the street to turn down.
2. something used to mark the boundary of land.
3. a building or other place that is of outstanding historical, aesthetic, or cultural importance, often declared as such and given a special status (landmark designation) , ordaining its preservation, by some authorizing organization.
4. a significant or historic event, juncture, achievement, etc.: The court decision stands as a landmark in constitutional law.
v.t.
5. to declare (a building, site, etc.) a landmark: a movement to landmark New York's older theaters.
[ bef. 1000; ME; OE landmearc. See LAND, MARK 1 ]
Syn. 4. milestone, watershed, benchmark.