underlie
Americanverb (used with object)
-
underlies,
present (3rd person singular)
-
underlay,
past
-
underlain,
past participle
-
underlying
present participle
-
to lie under or beneath; be situated under.
-
to be at the basis of; form the foundation of.
-
Grammar. to function as the root morpheme or original or basic form of (a derived form).
The form “boy” underlies “boyish.”
-
Finance. to be primary to another right or security.
verb
-
to lie or be placed under or beneath
-
to be the foundation, cause, or basis of
careful planning underlies all our decisions
-
finance to take priority over (another claim, liability, mortgage, etc)
a first mortgage underlies a second
-
to be the root or stem from which (a word) is derived
"happy" underlies "happiest"
Other Word Forms
Derived Forms
Inflected Forms
Participles
Conjugated Forms
Present
-
underliesimple
-
underliessimple
-
have underlainperfect
-
has underlainperfect
-
am underlyingprogressive
-
are underlyingprogressive
-
is underlyingprogressive
-
have been underlyingperfect progressive
-
has been underlyingperfect progressive
Past
-
underlaysimple
-
had underlainperfect
-
was underlyingprogressive
-
were underlyingprogressive
-
had been underlyingperfect progressive
Future
Etymology
Origin of underlie
before 900; Middle English underlyen (v.), Old English underlicgan. See under-, lie 2
Explanation
While it’s true that when something underlies something else, it is beneath it, this does not necessarily mean subservience — it can also indicate a strong foundation or bedrock that underlies, or supports, an idea or decision. The Old English word underlicgan meant to serve or submit to another, and that meaning does carry through to the modern word underlie — to a point. Although still referring to something under something else, around 1850 the meaning of the verb shifted to include something that makes a foundation for something else. For example, one factor that underlies a patient's unusual symptoms might be his recent trip to a foreign country, where he could have picked up a local infection.
Vocabulary lists containing underlie
The Thing About Jellyfish
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 Hand of Fatima" and "Old Ways, 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!
Florida's B.E.S.T. Common Prefixes: under-
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.
See Examples For:
Open-weight models typically share only the numerical parameters, or “weights,” that underlie them, while true open-source models allow full access to training data and code.
From The Wall Street Journal ● Aug. 18, 2026
"A similar mechanism could underlie individual differences in responses to other rewarding stimuli," says author and neuroscientist Josep Marco-Pallarés of the University of Barcelona.
From Science Daily ● Jan. 12, 2026
Talk to some folks in your family whom you trust to make sure you’re not overstepping any unspoken boundaries that underlie family relationships.
From MarketWatch ● Dec. 15, 2025
It was there he learned the Socratic method of inquiry by oral combat that would underlie both his remarkable achievements and the harsh judgments that would precipitate his fall from grace.
From Los Angeles Times ● Nov. 7, 2025
They concluded: The “motivation to disclose our internal thoughts and knowledge to others may serve to sustain the behaviors that underlie the extreme sociality of our species.”
From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel
That underlies the name of a new exhibition at the California Museum in Sacramento, “Help Wanted/Leave Now!” about the “revolving door” of programs and practices that have alternately enticed and expelled workers, legal and undocumented.
From Los Angeles Times ● Sep. 9, 2026
Keeping such power a safe distance from Israeli civilians underlies the thinking, and the subsequent action.
From The Wall Street Journal ● Jul. 12, 2026
But five days after that, the DOJ notified the court in the Texas case that “the government has decided to maintain the definition” that underlies the ghost gun rule.
From Salon ● Jun. 2, 2026
"And that motive likely underlies this launch as well," he added.
From Barron's ● Mar. 14, 2026
Linguists term this decisive innovation, which also underlies puns today, the rebus principle.
From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond
In postproduction, Del Toro sometimes underlay Elordi’s screams with his own guttural noises or the roars of lions and gorillas, imagining a voice created by mismatched lungs and a throat from different people.
From The Wall Street Journal ● Sep. 30, 2025
However, Sidony says her flooring was never inspected, and has shown the BBC her end of tenancy agreement which instructed her to remove carpets, underlay, gripper rods and laminate flooring.
From BBC ● Nov. 27, 2024
The turf was intended to function as an underlay for a plastic liner atop it as part of a construction project.
From Seattle Times ● Nov. 22, 2023
When his music was combined with Lynch’s “Blue Velvet,” audiences got to experience a gorgeous melody atop a disturbing, abstract underlay.
From Los Angeles Times ● Dec. 12, 2022
Over time, observation became an adjunct to experiment, both producing reliable facts in place of the unreliable, unspecific ‘experience’ which underlay so much classical and medieval discussion.
From "The Invention of Science" by David Wootton
A fundamental tension has always underlain the history of the Civil Rights movement, much as it did contemporaneous news coverage.
From The Wall Street Journal ● May 3, 2026
Part of the reasoning in 2018 was site investigations found the ground underlain with peat deposits, as well as toxic and phytotoxic - meaning poisonous to plants - risk from shallow soils.
From BBC ● Nov. 15, 2025
Approximately 91 per cent of these forests in the northern hemisphere are underlain by permafrost.
From Science Daily ● Nov. 9, 2023
The drill site in northwest Greenland was 138 miles from the coast and underlain by 4,560 feet of ice.
From Salon ● Jul. 23, 2023
The Loudoun sandy loam consists of from 8 to 12 inches of a heavy brown or gray sandy loam, underlain by a heavy yellow or red loam or clay loam.
From History and Comprehensive Description of Loudoun County, Virginia by James William Head
Meanwhile, for the current year, AXA forecasts underlying earnings of about 8.6 billion euros, which compares with 8.4 billion euros in 2025.
From The Wall Street Journal ● Sep. 15, 2026
Without higher energy prices and tariffs, underlying inflation would be closer to 2.5%, not far above the Fed’s 2% target, he said.
From MarketWatch ● Sep. 14, 2026
Because the study examined genetic activity related both to GLP-1 use and to hair loss, the researchers say the overlapping genetic risk suggests that the two may share an underlying biological connection.
From Science Daily ● Sep. 13, 2026
Health officials in Michigan said that the two deaths, which both happened in the state, were of people who had "significant underlying health conditions that may have been impacted by cyclosporiasis and dehydration".
From BBC ● Sep. 12, 2026
Although she worked a full-time job while in custody, most of her income went to repay the diversion program, not the underlying fine that put her in custody in the first place.
From "The New Jim Crow" by Michelle Alexander
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.
