countless

adjective

count·​less ˈkau̇nt-ləs 

: too numerous to be counted : myriad, many

countlessly adverb

Synonyms of countless

• many
• numerous
• innumerable
• numberless

Examples of countless in a Sentence

There are countless reasons why that would not be a good idea.

I've been there countless times.

Recent Examples on the Web

Chris Martin performs onstage in front of countless celebrities at the 2026 Heart Gala in Los Angeles on April 18. —Toria Sheffield, PEOPLE, 21 Apr. 2026

Thanks to its high altitude and exceptionally dark skies, this location offers stunning views of the Milky Way and countless stars. —Daisy Dobrijevic, Space.com, 21 Apr. 2026

Hundreds of passengers on an Amtrak train in Florida were left stranded for nearly 24 hours after wildfires broke out near the tracks — disrupting service, halting travel and leading to countless complaints. —Kelly McGreal, FOXNews.com, 21 Apr. 2026

Ever since, scientists have conducted countless studies that affirm his theory. —Greg Eghigian, The Conversation, 20 Apr. 2026

Word History

First Known Use

1593, in the meaning defined above

Kids Definition

countless

adjective

count·​less ˈkau̇nt-ləs 

: too numerous to be counted : innumerable