from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A landmark visible from the sea, used as a guide in navigation.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any elevated object on land which serves as a guide to mariners, such as a hill or steeple.
- n. A beacon, buoy, etc. placed in the sea to aid navigation.
from the GNU version of the Collaborative International Dictionary of English
- n. Any elevated object on land which serves as a guide to mariners; a beacon; a landmark visible from the sea, as a hill, a tree, a steeple, or the like.
from The Century Dictionary and Cyclopedia
- n. Any elevated object on land which serves for a direction to mariners in entering a harbor, or in sailing along or approaching a coast; a beacon, as a light-house, a mountain, etc.
sea + mark. Compare landmark. (Wiktionary)