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

Your athletic endeavors are now about maintenance, not milestones. —Zach Przystup, Baltimore Sun, 27 Apr. 2026

The five releases are hitting the streets a year before the Jazz Showcase’s 80th anniversary — a remarkable milestone for a jazz-only venue. —Hannah Edgar, Chicago Tribune, 27 Apr. 2026

The couple has included their children in several of the pregnancy milestones, including a visit to the doctor for Whitney's 20-week ultrasound. —Charna Flam, PEOPLE, 27 Apr. 2026

Chris Brown, Usher tour in the works The fatherhood milestone comes as Brown is set to embark on a coheadlining tour with fellow R&B icon Usher this summer. —Edward Segarra, USA Today, 27 Apr. 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