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

Although the storefront marks a significant milestone, Thomas says the business has always been about preparing his daughters for the future rather than simply increasing sales. — Kansas City Star, 26 July 2026

Pederson is the second to accomplish the milestone against the Mariners this year; outfielder Brandon Nimmo got his 1,000th career hit against the Mariners on April 18. — Cal Phillips updated July 24, Fort Worth Star-Telegram, 25 July 2026

The burn went off without a hitch — a milestone since SpaceX had not always performed the burn if a test didn't go smoothly. — Tariq Malik, Space.com, 25 July 2026

Families are using travel to celebrate milestones, reconnect across generations or simply spend uninterrupted time together. — Judy Koutsky, Forbes.com, 25 July 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