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

For all of this and more, multi-generational families, married couples celebrating milestone anniversaries, and celebrities looking for privacy and discretion flock here. — Condé Nast, Condé Nast Traveler, 6 Oct. 2026

This marks another notable milestone in the brand’s global trajectory. — Footwear News, 6 Oct. 2026

Several acts on the bill are marking milestones of their own. — Jessica Lynch, Billboard, 6 Oct. 2026

Jason Klarman, chief digital officer for Fox News Media, who was part of the channel’s launch marketing team way back in the early Clinton era, discusses the milestone anniversary and the era of media in which Fox News Channel was born. — Cynthia Littleton, Variety, 5 Oct. 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