A milestone in a baby's life is when they learn how to walk.
The invention of the railroad was a milestone in the history of transportation.
Do you remember what the milestone is to find the old country road?
When writing her autobiography, Alice tried to highlight all of the milestones in her success.
Graduation is a huge milestone in a young adult's life.
Reaching the next milestone in success would require hours of hard work.
Abolishment of slavery was a huge milestone in America's history.
What do you think has been the biggest milestone in your personal growth?
Did we already pass the milestone where we were supposed to make a turn?
It's easy to miss the road to our house, but there is a milestone on the highway to remind you where the exit is.