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

Most recently, Damon added another major milestone by winning the 2025 USA Boxing National Championships and earning a spot on Team USA's national youth roster. —Nina Burns, CBS News, 8 Jan. 2026

Alpha prototype marks a major milestone in humanoid robotics, arriving after just seven months of development. —Aamir Khollam, Interesting Engineering, 8 Jan. 2026

Despite their franchise history dating back to the mid-70s (via Kansas City and Colorado), which includes essentially all of the highest-scoring era in league history, the New Jersey Devils have never had a player hit either of the game’s most basic offensive milestones. —Sean McIndoe, New York Times, 7 Jan. 2026

San Jose’s quest to build a robust entertainment lineup around the major sporting events coming to Silicon Valley in 2026 has hit a key fundraising milestone, with several local and national companies and philanthropic organizations chipping in big bucks. —Devan Patel, Mercury News, 7 Jan. 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