milestone

[ mahyl-stohn ]
/ ˈmaɪlˌstoʊn /

noun

a stone functioning as a milepost.
a significant event or stage in the life, progress, development, or the like of a person, nation, etc.: Her getting the job of supervisor was a milestone in her career.

Origin of milestone

First recorded in 1740–50; mile + stone

Example sentences from the Web for milestone

British Dictionary definitions for milestone

milestone
/ (ˈmaɪlˌstəʊn) /

noun

a stone pillar that shows the distance in miles to or from a place
a significant event in life, history, etc