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 of milestone

• 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

Despite a few glimmers of good feeling, today's fierce political divisions have redefined a milestone that has often been marked by unity and optimism, at least for a moment. —Susan Page, USA Today, 22 June 2026

Even in the modern era, few mortals can achieve such milestone anniversaries, at least not without the help of a cryogenic freezer. —Hillary Busis, Vanity Fair, 22 June 2026

This milestone required sustained partnership between the state of Maryland, the federal government, local communities and private industry. —Wes Moore, Baltimore Sun, 22 June 2026

SpaceX just notched a remarkable launch-dominance milestone. —Mike Wall, Space.com, 22 June 2026

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