milestone

noun

mile·​stone ˈmī(-ə)l-ˌstōn 

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

• milestone 1

Synonyms

• climax
• landmark
• watershed
• corner

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 chipmaker closed above that milestone Thursday as CNBC reported that the technology titan met with President Donald Trump. —Samantha Subin, CNBC, 11 July 2025

The club officially kicked off celebration of its milestone April 27 as past and current members gathered at the Point Loma Assembly Hall to reflect and look ahead. —Madison Beveridge, San Diego Union-Tribune, 11 July 2025

The production, directed by Michael Mayer and choreographed by Steven Hoggett, marks this therapy milestone by having backup singers and chorus members emerge from behind Neil’s chair. —Los Angeles Times, 11 July 2025

The Nashville rocker's wife, Olivia Jean, gifted him the device for his milestone birthday on July 9. —Audrey Gibbs, The Tennessean, 10 July 2025

Word History

First Known Use

1662, in the meaning defined at sense 1

Rhymes for milestone

• acetone
• anglophone
• baritone
• bourguignon
• buspirone
• chaperon
• chaperone
• cobblestone
• collarbone
• cornerstone
• cortisone
• dictaphone

Kids Definition

milestone

noun

mile·​stone ˈmī(ə)l-ˌstōn 

1

: a milepost made of stone

2

: an important point in progress or development