insubstantial
Americanadjective
-
not substantial or real; lacking substance.
an insubstantial world of dreams.
-
not solid or firm; weak; flimsy.
-
not substantial in amount or size; inconsiderable.
an insubstantial sum.
adjective
-
not substantial; flimsy, tenuous, or slight
-
imaginary; unreal
Other Word Forms
- insubstantiality noun
- insubstantially adverb
Etymology
Origin of insubstantial
From the Late Latin word insubstantiālis, dating back to 1600–10. See in- 3, substantial
Explanation
Insubstantial is an adjective that means lacking form, substance or nutritional value. If you're really hungry, a bowl of clear broth will seem pretty insubstantial. If there is insubstantial evidence to convict an accused criminal, he will be set free. In the office, insubstantial expenses should be paid out of the petty cash draw. A thin blouse is too insubstantial to be worn in this cold weather. And a candy bar makes an insubstantial lunch — a sandwich and fruit would be more nutritious.
Vocabulary lists containing insubstantial
The Grapes of Wrath
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!
The Graveyard Book
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!
The Tempest
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.
Scarlet’s good intentions to end wars by way of sheer determination to do what’s right might prove insubstantial in practice.
From Los Angeles Times • Feb. 6, 2026
But CBS is already full of people who think they know what they’re doing, who believe they represent hallowed tradition, the so-called Tiffany network, against which the Free Press must seem a tad insubstantial.
From The Wall Street Journal • Oct. 7, 2025
The UN's cultural agency said that despite "significant growth in production", the business of film-making across the continent was hindered by issues such as piracy, insubstantial training opportunities and a lack of official film institutions.
From BBC • Oct. 22, 2024
The ads that failed were ultimately insubstantial, or otherwise objectionable.
From Slate • Feb. 12, 2024
“Poor little soul,” said Mistress Owens, taking the boy from her, and cradling him in her capable, if insubstantial arms.
From "The Graveyard Book" by Neil Gaiman
![]()
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.