too numerous to be counted
"countless hours"
"an infinite number of reasons"
"innumerable difficulties"
"the multitudinous seas"
"myriad stars"
Too many to count; innumerable or incalculable
"The traveler was struck by countless stars twinkling above the vast desert night."
In plain English: Countless means so many that it is impossible to count them all.
"Countless people gathered in the square to celebrate the holiday."
Usage: Use countless before singular nouns like countless problems, but remember that the word implies an uncountably large number rather than literally being impossible to tally. It is often interchangeable with innumerable when emphasizing a vast quantity of items.
Countless is formed by combining the word count with the suffix -less to mean without a number that can be counted. This straightforward construction has remained consistent since its creation, directly describing something too numerous to tally.