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

Hours after Dundee’s Professor Iris Grunwald performed the world’s first remote thrombectomy on a human cadaver, another milestone followed. —Neetika Walter, Interesting Engineering, 11 Nov. 2025

The pay package for Musk, already the world's richest person, consists of 12 tranches of shares to be granted if Tesla hits certain milestones over the next decade. —Lora Kolodny, CNBC, 11 Nov. 2025

Family Guy will launch its 24th season a week prior for a milestone Sunday featuring Episode 450 of Family Guy and Episode 800 of The Simpsons. —Nellie Andreeva, Deadline, 11 Nov. 2025

In the first half of 2025, for the first time ever, renewables overtook coal as the top source of global electricity — a major milestone, according to analysts. —Laura Paddison, CNN Money, 11 Nov. 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