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

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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

Iammarino's milestone coincidentally came against a former assistant in Woodridge's Jeff Decker, who served as defensive coordinator on Chagrin Falls' state final teams in 2010 and '09. Matt Goul,, "Riverside meets Lima halfway in classy move: HS football quick hits," 16 Sep. 2019 Only about 39 percent of Alabama mothers are still breastfeeding by the time their babies reach 6 months old, the milestone recommended by the American Academy of Pediatrics. Anna Claire Vollers |, al, "Alabama lacks workplace protections for moms who want to breastfeed," 16 Sep. 2019 Marcus Semien hit his 30th home run of the season, closing a couple milestones for the A’s. Shayna Rubin, The Mercury News, "Athletics break 23-year record, sweep Rangers," 15 Sep. 2019 Educators say the new spending on mental health could deliver a big payoff in graduation rates and other achievement milestones. oregonlive, "Oregon will spend big to promote youth mental health at school," 14 Sep. 2019 The milestone homer , a three-run drive in the seventh inning by Jonathan Villar, carried Baltimore past the Los Angeles Dodgers 7-3 Wednesday night. David Ginsburg, Houston Chronicle, "Jonathan Villar hits MLB record-setting HR in Orioles' win over Dodgers," 11 Sep. 2019 To celebrate the milestone, Wells posted some selfies of Sarah and him getting cozy in the backseat of a car. Jasmine Gomez, Seventeen, "A Complete Timeline of Sarah Hyland and Wells Adams' Relationship," 11 Sep. 2019 The news comes just weeks after a team of veterinarians achieved another milestone by harvesting 10 oocytes from the last two remaining female northern white rhinos living in Kenya. Abdi Latif Dahir, Quartz Africa, "Scientists have successfully created embryos of the near-extinct northern white rhino," 11 Sep. 2019 That milestone recently was adjusted to September 2022, but the contracting team now projects it will be reached in December 2022. Jon Murray, The Denver Post, "Interstate 70 expansion in Denver faces likely delay, contractor says," 9 Sep. 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.

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First Known Use of milestone

1662, in the meaning defined at sense 1

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Statistics for milestone

Last Updated

19 Sep 2019

Look-up Popularity

Time Traveler for milestone

The first known use of milestone was in 1662

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More Definitions for milestone



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.

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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).


concealment of treason or felony

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