underlie
Americanverb (used with object)
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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.”
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Finance. to be primary to another right or security.
verb
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to lie or be placed under or beneath
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to be the foundation, cause, or basis of
careful planning underlies all our decisions
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finance to take priority over (another claim, liability, mortgage, etc)
a first mortgage underlies a second
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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
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have underlainperfect
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has underlainperfect
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am underlyingprogressive
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are underlyingprogressive
-
is underlyingprogressive
-
have been underlyingperfect progressive
-
has been underlyingperfect progressive
Past
-
underlaysimple
-
had underlainperfect
-
was underlyingprogressive
-
were underlyingprogressive
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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
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"The Hand of Fatima" and "Old Ways, New World"
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Florida's B.E.S.T. Common Prefixes: under-
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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:
True open-source models allow full access to training data and code, while open-weight models share the numerical parameters, or “weights,” that underlie them.
From The Wall Street Journal ● Mar. 18, 2026
This process is thought to underlie decisions, thoughts, and memories, and studying it directly could help explain how the brain performs complex computations.
From Science Daily ● Dec. 29, 2025
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
At some central banks, policymakers agree to a path for interest rates that underlies the forecast.
From MarketWatch ● Oct. 16, 2026
That historical constraint helped researchers improve their measurement of the half-life governing the decay of potassium-40 into argon-40, the process that underlies argon-argon dating.
From Science Daily ● Sep. 30, 2026
It also required him understanding that what underlies the struggles between millennials and their parents is how shockingly alike they are despite being constantly annoyed by each other.
From Los Angeles Times ● Sep. 1, 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
This is the conception of life which underlies the Norse religion, as somber a conception as the mind of man has ever given birth to.
From "Mythology: Timeless Tales of Gods and Heroes" by Edith Hamilton
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
He stood on the edge of the sandrock shelf that underlay Laguna and looked east across the river before dawn.
From "Ceremony:" by Leslie Marmon Silko
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
The slope is steep and underlain by weak, heavily fractured bedrock, making it prone to failure.
From Science Daily ● Dec. 21, 2025
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 region is underlain by quartz veins, rich in ore.
From Seattle Times ● May 22, 2023
But the adoption of the initiative and the referendum substitutes a new principle for the one which has hitherto underlain American local institutions.
From The Promise of American Life by Herbert David Croly
In its quarterly outlook report, the central bank said underlying inflation has reached roughly 2%, marking a historic turning point in its long battle to achieve sustainable price growth.
From The Wall Street Journal ● Oct. 30, 2026
Their underlying claim isn’t that modern people have lost their sense of smell, but that we have grown less able to interpret what it tells us.
From The Wall Street Journal ● Oct. 30, 2026
In mathematics and physics, self-similar solutions describe patterns that retain their underlying structure when viewed at different scales.
From Science Daily ● Oct. 29, 2026
But Temple and his collaborators began questioning whether the underlying mathematics could remain stable, prompting them to investigate other possible explanations for the observed acceleration.
From Science Daily ● Oct. 29, 2026
There is an underlying force that drives together the several creatures comprising myxotricha, and, then drives the assemblage into union with the termite.
From "The Lives of a Cell" by Lewis Thomas
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