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

The moment marked a personal milestone for Baldwin, who said goodbye to dancing 16 years ago after breaking her hip due to overuse. —Amanda Castro, MSNBC Newsweek, 17 Sep. 2025

Denholm is giving interviews to explain the board’s decision to award Musk a pay package that could be worth $1 trillion if the company hits milestones for market capitalization, profits, and vehicle production. —Liz Hoffman, semafor.com, 16 Sep. 2025

James Tour, professor of chemistry and materials science at Rice, called the achievement an industrial milestone. —Aamir Khollam, Interesting Engineering, 16 Sep. 2025

Companies emerging from the lab are often too far along for R&D grants but not far enough to meet the milestones venture capitalists expect. —Rhonda Richford, Footwear News, 16 Sep. 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