milestone

noun mile·stone \ ˈmī(-ə)l-ˌstōn \

Definition of milestone

1 :a stone serving as a milepost (see milepost 1)
2 :a significant point in development
  • Graduating from college was an important milestone in her life.

Examples of milestone in a Sentence

  1. the new drug was regarded as a milestone in the treatment of heart disease

Recent Examples of milestone from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'milestone.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Illustration of milestone

First Known Use of milestone

1662

Other Transportation Terms


MILESTONE Defined for English Language Learners

milestone

noun

Definition of milestone for English Language Learners

  • : a stone by the side of a road that shows the distance in miles to a specified place

  • : an important point in the progress or development of something : a very important event or advance


MILESTONE Defined for Kids

milestone

noun mile·stone \ ˈmīl-ˌstōn \

Definition of milestone for Students

1 :a stone by the side of a road showing the distance in miles to a given place
2 :an important point in progress or development His discovery was a major milestone in scientific research.


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