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

But alcohol’s ubiquity persists in the face of mountains of research linking heavy drinking to cancer, heart disease, stroke, cognitive decline, developmental disorders, gun violence, injuries, and countless other consequences. —Lev Facher, STAT, 12 May 2026

My stylist, Roger Forker, has designed all my costumes for countless amounts of roasts. —Ethan Shanfeld, Variety, 12 May 2026

That these professionals are even in contact despite the countless logistical barriers between them is reason enough to celebrate. —Alison Foreman, IndieWire, 12 May 2026

There are plenty of moms who’ve spent countless hours driving, feeding and motivating their sports-playing sons and daughters through highs and lows. —Eric Sondheimer, Los Angeles Times, 10 May 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