A milestone is an important event in the history or development of something or someone.
例句
He said the launch of the party represented a milestone in Zambian history...他說該黨的創立是贊比亞歷史上的一個里程碑。Starting school is a milestone for both children and parents.對于孩子和家長而言，開始上學是一件大事。
N-COUNT
（路邊顯示到某地距離的）里程碑，里程標志
A milestone is a stone by the side of a road showing the distances to particular places.
英漢詞典釋義
n.
重要事件;重要階段;轉折點;里程碑
Several important milestones in foreign policy have been passed by this Congress and they can be chalked up as major accomplishments.這次代表大會通過了對外政策中幾起劃時代的事件,并且它們可作為主要成就記錄下來。The company passed the ￡6 million milestone this year.今年公司越過了600 萬英鎊這個里程碑式的數字。The film proved to be a milestone in the history of cinema.事實證明這部影片是電影史上的一個里程碑。“Our work”, he continued, warming to his theme, “will be a milestone in scientific history.”“我們的工作， ”他說到這一話題來了勁，“將會是科學史上的里程碑。 ”
英英詞典釋義
Noun
1. stone post at side of a road to show distances
2. a significant event in your life (or in a project)