land·mark 
(lăndmärk′)
(lăndmärk′)n.
1. A prominent identifying feature of a landscape.
2. A fixed marker, such as a concrete block, that indicates a boundary line.
3. An event marking an important stage of development or a turning point in history.
4. A building or site with historical significance, especially one marked for preservation by a municipal or national government.
adj.
Having great import or significance: a landmark court ruling.
tr.v. land·marked, land·mark·ing, land·marks
To accord the status of a landmark to; declare to be a landmark.
- second baseman
- second best
- second-best
- second blessing
- second childhood
- second class
- second-class
- second class
- Second Coming
- second cousin
- second-degree burn
- Second Empire
- second fiddle
- second-generation
- second growth
- second-guess
- second-guesser
- second hand
- second hand
- secondhand
- secondhand smoke
- second home
- secondi
- second lieutenant
- second line