mile·​stone | \ ˈmī(-ə)l-ˌstōn How to pronounce milestone (audio) \

Definition of milestone

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

Illustration of milestone

Illustration of milestone

milestone 1

Keep scrolling for more

Examples of milestone in a Sentence

the new drug was regarded as a milestone in the treatment of heart disease
Recent Examples on the Web The milestone for Hubei province comes as China struggles to get back on its feet after being flattened by a disease that exploded out of the city of Wuhan in late January. Rachel Chang, Fortune, "China’s coronavirus epicenter reaches milestone of zero new cases," 19 Mar. 2020 The data mark a significant milestone for the entertainment industry, which has seen rapid shifts in consumer behavior in recent years because of the rise of streaming services including Netflix and its . Ryan Faughnder, Los Angeles Times, "Digital entertainment spending passes global box office as streaming transforms Hollywood," 11 Mar. 2020 Amanda Anderson and her friends wanted to experience cherry blossom season and celebrate a friend's milestone birthday in Japan this spring. David Oliver, USA TODAY, "Making travel plans? How coronavirus fear is spreading and putting trips in limbo," 2 Mar. 2020 The milestone birthday is finally here and Millie is celebrating hard. Kelsey Stiegman, Seventeen, "Millie Bobby Brown Went Full on ‘90s for Her 16th Birthday Party," 19 Feb. 2020 The coordinated resolution of the four-year-long investigations into the European plane maker represents a milestone for France, which previously had been criticized for failing to hold companies accountable for foreign bribery. Kristin Broughton, WSJ, "Airbus Settlement Signals Greater Collaboration on International Bribery Cases," 3 Feb. 2020 Despite hitting the milestone birthday, King reflected on still feeling youthful when one dinner guest asked her what the biggest surprise has been about turning 65. Claudia Harmata,, "Oprah Winfrey Celebrates BFF Gayle King’s 65th Birthday with Special Dinner Party," 30 Dec. 2019 Today, exactly 200 years later, thousands are expected to fill the streets of Alabama’s capital city to celebrate this milestone birthday., al, "Alabama 200: Events today celebrate milestone birthday," 14 Dec. 2019 See their sweet tributes, and learn more about Kirk's career and family life. Kirk Douglas is celebrating a milestone birthday. Megan Stein, Country Living, "Kirk Douglas Is 103! See Catherine Zeta-Jones's Sweet Tribute to the Legendary Actor," 9 Dec. 2019

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.

See More

First Known Use of milestone

1662, in the meaning defined at sense 1

Keep scrolling for more

Learn More about milestone

Time Traveler for milestone

Time Traveler

The first known use of milestone was in 1662

See more words from the same year

Statistics for milestone

Last Updated

3 Apr 2020

Cite this Entry

“Milestone.” Dictionary, Merriam-Webster, Accessed 3 Apr. 2020.

Keep scrolling for more

More Definitions for milestone


How to pronounce milestone (audio)

English Language Learners Definition of milestone

: 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


mile·​stone | \ ˈmīl-ˌstōn How to pronounce milestone (audio) \

Kids Definition of milestone

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.

Keep scrolling for more

Comments on milestone

What made you want to look up milestone? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

Name that Thing: Flower Edition

Spell It

Can you spell these 10 commonly misspelled words?

Syn City

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!