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 deal comes after nearly a year of negotiations and represents a significant milestone for Indian content creation, moving away from unauthorized adaptations that have plagued the industry in previous decades. —Naman Ramachandran, Variety, 4 Aug. 2025

The Busan International Film Festival is marking its milestone 30th edition this year, with veteran actor Lee also serving as the host for the festival’s opening ceremony. —Sara Merican, Deadline, 4 Aug. 2025

His comments to reporters in early July came as the House concluded a more than seven-hour vote, then the longest in the chamber’s history (a milestone hit after the chamber had already broken the record a week earlier). —Savannah Kuchar, USA Today, 3 Aug. 2025

Cult western favourite The Quick And The Dead turns 30 this year – a milestone Sony Pictures Home Entertainment has happily decided to celebrate by releasing the film on a new limited edition Steelbook 4K Blu-ray. —John Archer, Forbes.com, 1 Aug. 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