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

Are there company-specific milestones that make transitioning out more or less natural (such as the integration of a major acquisition, the launch of an important new product, or the completion of a long-running project)? —Kurt Strovink, Fortune, 7 Oct. 2025

That second reception marked a historic milestone. —Cole Sullivan, MSNBC Newsweek, 7 Oct. 2025

Mark the milestone of purchasing a first home with stationery featuring their brand new address. —Kristi Kellogg, Architectural Digest, 7 Oct. 2025

The video opened with a breakfast spread and a graphic celebrating her milestone streak on the popular language-learning app. —Janine Henni, PEOPLE, 6 Oct. 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