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

That doesn’t include thousands of kinds of insects and other invertebrates known to live in the Okefenokee, plus countless others yet to be documented by humans. — Drew Kann, AJC.com, 20 July 2026

Even after countless long-haul flights, all of the straps and zippers are good as new. — Elly Leavitt, Vogue, 19 July 2026

The material doesn’t pill and has held up after countless washes. — Rylee Johnston, PEOPLE, 19 July 2026

The 78-year-old music venue, still standing amid the crumbling history around it, including the construction of a subway stop next door, has hosted countless legends on its stage. — Karen Bliss, Rolling Stone, 18 July 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