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

This year, there’s another one worth celebrating, one that just hit a milestone birthday. —Cheryl Russell, Oc Register, 18 May 2026

Here’s a look at the major career milestones of Adriano Goldschmied. —Maria Cristina Pavarini, Footwear News, 18 May 2026

As a grandmother to Jason’s daughters, Wyatt (six), Elliotte (five), Bennett (three), and Finnley (one), Donna rarely misses a major milestone. —Michael Gioia, Architectural Digest, 18 May 2026

Just in Time is only the musical to have announced recoupment from its season and one of only a few in the recent years to reach that milestone, including The Outsiders (from the 2024-25 season), Six (2021-22) MJ (2021-22) & Juliet and Moulin Rouge! —Caitlin Huston, HollywoodReporter, 18 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