资料来源 : pyDict

里程碑,里程石,一里程标

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Milestone \Mile"stone`\, n.
   A stone serving the same purpose as a milepost.

资料来源 : WordNet®

milestone
     n 1: stone post at side of a road to show distances [syn: {milepost}]
     2: a significant event in your life (or in a project)