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 leader of the $1 billion-a-year in revenue breakfast and lunch chain takes time each month to handwrite congratulations to cooks and dishwashers celebrating major milestones, like 10, 20, or even 30 years with the company. —Preston Fore, Fortune, 21 Oct. 2025

The opening of the CMCC is a major milestone in the implementation of the historic deal. —Rachel Wolf, FOXNews.com, 21 Oct. 2025

The toy deal is a milestone but not the first major consumer products push for Netflix. —Dade Hayes, Deadline, 21 Oct. 2025

She has been involved for 30 years, a milestone that was celebrated with a lighting of the Empire State Building in pink to honor the cause at the start of the month. —Karla Rodriguez, Footwear News, 21 Oct. 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