n. 里程标志, 里程碑

[ noun ]
stone post at side of a road to show distances
<noun.communication>

Milepost \Mile"post`\, n.
1. A post, or one of a series of posts, set up to indicate
spaces of a mile each or the distance in miles from a
given place.

2. An event or accomplishment marking a significant advance
in an endeavor; a notable achievment; as, putting a man in
orbit was a big milepost on the way to the moon.

Syn: milestone.
[PJC]