milestone

noun
UK /ˈmaɪl.stəʊn/
US /ˈmaɪl.stoʊn/

A milestone is an important moment or event in your life.

Learning to ride a bike was a big milestone for me.


OTHER MEANINGS

2. A stone beside a road that shows how far you have traveled.

We stopped by the milestone to check the distance to the next town.

3. A significant stage in the development of a project or process.

Finishing the first draft was a major milestone in the project.

4. A marker used to measure distance along a route.

The old milestones along the highway date back a hundred years.