porthole
Americannoun
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a round, windowlike opening with a hinged, watertight glass cover in the side of a vessel for admitting air and light.
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an opening in a wall, door, etc., as one through which to shoot.
noun
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Sometimes shortened to: port. a small aperture in the side of a vessel to admit light and air, usually fitted with a watertight glass or metal cover, or both
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an opening in a wall or parapet through which a gun can be fired; embrasure
Etymology
Origin of porthole
Explanation
When you get the window seat on an airplane, you'll be sitting beside a porthole, which is the name for a window on an aircraft or ship. It might sound fun to go on an ocean cruise — but it'll cost extra to stay in a cabin with a porthole. Originally, porthole applied only to the round windows on ships, initially used for firing weapons, and later simply a way to let in light and air. Though port is a common nautical term, porthole has a different source: the French porte, or "door," which first referred to the windows' watertight covers.
Vocabulary lists containing porthole
"Rogue Wave," Vocabulary from the short story
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Lesson 1
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"Rogue Wave" by Theodore Taylor
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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.
He was a 25-year-old tinkering with self-tanners, but all the intrigue and action seemed to be around the lab next door, with its strange music, flashing lights and tinfoil covering the porthole.
From The Wall Street Journal • Mar. 18, 2026
He’s even built a concrete fire shelter against a hillside with two steel escape doors and porthole windows.
From Los Angeles Times • Nov. 24, 2025
The scan shows new close-up details, including a porthole that was most likely smashed by the iceberg.
From BBC • Apr. 8, 2025
Back then, it looked like something out of a science-fiction film: a futuristic tower composed of 140 detachable, single-resident capsules with porthole windows, like a pile of eyes fixed on the city.
From New York Times • Jan. 17, 2024
Renata leaned toward the porthole and together they gazed out.
From "Wolfie & Fly" by Cary Fagan
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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.