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

Ever since then, Mitchell has accomplished many major milestones, representing Team USA four times in the Paralympic Games. —Donald Fountain, CBS News, 4 May 2026

At a recent appearance, the actress reflected on some of the milestones along the way, including an early appearance on Happy Days. —Staff Author, PEOPLE, 4 May 2026

Bitcoin topped $80,000 over the weekend for the first time since January, and was last trading above that milestone. —Christina Cheddar Berk,davis Giangiulio, CNBC, 4 May 2026

Sebago is also taking its birthday milestone celebrations on the road with its new boat tour across Europe. —Stephen Garner, Footwear News, 3 May 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