n. A boundary-mark to a tract of land; one of the fixed objects used to designate the limits of a farm, town, or other piece of territory, as monumental stones, marked trees, or ditches.n. Any specific or prominent object marking a locality or historically associated with a locality; a hill, tree, house, or other feature of a landscape that may serve as a guide; especially, some object on land by which a locality may be recognized by persons at sea.n. Figuratively, a distinguishing characteristic, variation, or event; that which marks a turning-point; something that serves to distinguish a particular period of time or point in progress or transition: as, the landmarks of science or history.