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

Toney, who entered the game with 89 catches for 992 yards, hit the 1,000-yard mark on a 4-yard catch on Miami’s third drive of the game late in the first quarter — four plays after Fletcher’s run that got him to his milestone. —Jordan McPherson, Miami Herald, 1 Jan. 2026

However, Cooper was in Israel for work at the time and missed the major milestone. —Katie Mannion, PEOPLE, 1 Jan. 2026

But movement toward 2025 milestones is uneven, with the weakest results in goals that depend on suppliers, logistics partners, consumers or government policy. —Alexandra Harrell, Sourcing Journal, 31 Dec. 2025

Scientists operating the Wendelstein 7-X stellarator in Germany reached a major fusion milestone in 2025 by producing high-energy helium-3 ions for the first time. —Kaif Shaikh, Interesting Engineering, 31 Dec. 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