indistinguishable
Americanadjective
-
not distinguishable.
-
indiscernible; imperceptible.
adjective
-
identical or very similar (to)
twins indistinguishable from one another
-
not easily perceptible; indiscernible
Other Word Forms
- indistinguishability noun
- indistinguishableness noun
- indistinguishably adverb
Etymology
Origin of indistinguishable
First recorded in 1600–10; in- 3 + distinguishable ( def. )
Explanation
If you can't tell the difference between two things, they're indistinguishable — they appear the same. Although their parents can tell them apart, identical twins are indistinguishable to most people. It's easy to see which of two bills is worth twenty dollars and which is Monopoly money, but a professionally counterfeited bill is indistinguishable from a real one. One of the earliest uses of this word was by Shakespeare around 1600, when he gave it the meaning "of indeterminate shape." The definition evolved, first to "not clearly perceived," and then finally to "incapable of being told apart."
Vocabulary lists containing indistinguishable
Talk Like Shakespeare Day, List 1
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Brave New World
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Words with 15 or More Letters, List 1
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
A follow-up study in 2024 involving Flinders, Greifswald, and McMaster Universities showed that antibodies from vaccine-related and infection-related cases were indistinguishable.
From Science Daily • Apr. 10, 2026
The sensation became so consistently tied to breastfeeding that eventually, breastfeeding and that feeling were indistinguishable in my mind.
From Slate • Mar. 15, 2026
Since Cameo and OpenAI’s videos have included the same celebrities, “the two products may be indistinguishable to the consuming public,” the order stated.
From Los Angeles Times • Feb. 18, 2026
The regulations define synthetic data as information that "appears to be real" or is "likely to be perceived as indistinguishable from a natural person or real-world event."
From Barron's • Feb. 17, 2026
That is, time is imaginary and is indistinguishable from directions in space.
From "A Brief History of Time: And Other Essays" by Stephen Hawking
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
