Milepost
Part of speech: noun
Definition: A post on a highway, often with one or more fingerposts, showing the distance in miles to nearby places
Milestone
Part of speech: noun
Definition: A stone milepost (or by extension in other materials), one of a series of numbered markers placed along a road at regular intervals, typically at the side of the road or in a median.An important event in a person's life or career, in the history of a nation, in the life of some project etc.
Example sentence: Partnering up with the Monster Energy Outbreak Tour marks a milestone moment in my career.