sill
noun
a horizontal timber, block, or the like serving as a foundation of a wall, house, etc.
sill
1 American
[sil]
/ sɪl /
noun
-
sills
plural
-
a horizontal timber, block, or the like serving as a foundation of a wall, house, etc.
-
the horizontal piece or member beneath a window, door, or other opening.
-
Geology. a tabular body of intrusive igneous rock, ordinarily between beds of sedimentary rocks or layers of volcanic ejecta.
Sill
2
American
[sil]
/ sɪl /
noun
sill
British
/ sɪl /
noun
-
a shelf at the bottom of a window inside a room
-
a horizontal piece along the outside lower member of a window, that throws water clear of the wall below
-
the lower horizontal member of a window or door frame
-
a continuous horizontal member placed on top of a foundation wall in order to carry a timber framework
-
a flat usually horizontal mass of igneous rock, situated between two layers of older sedimentary rock, that was formed by an intrusion of magma
sill
Scientific
/ sĭl /
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of sill
before 900; Middle English sille, Old English syl, sylle; cognate with Low German süll, Old Norse syll; akin to German Schwelle sill
Vocabulary lists containing sill
Earth Science - Middle School
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Earth Science - High School
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Rocks and Minerals - Middle School and High School
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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:
The California Energy Commission, which tracks fuel inventory, said the state’s current jet fuel stock is sill sufficient.
From Los Angeles Times ● Apr. 24, 2026
The Red Sea was initially connected from the north to the Mediterranean through a shallow sill.
From Science Daily ● Oct. 8, 2025
“It’s the law,” the not-unkind super replies — though Alex, now 2, can barely sit up, let alone reach the sill.
From New York Times ● Apr. 23, 2024
The hearing was told Sir Bobby had lost his balance as he stood up from his chair, striking a window sill and "possibly a radiator".
From BBC ● Nov. 1, 2023
Only now Mariam saw a basket on the sill.
From "A Thousand Splendid Suns" by Khaled Hosseini
Sill, Emanuel concludes: “With none of the flags pointing to elevated systemic risks, EVR ISI Strategy continues to see S&P 500 ending 2026 at 7,750, with the potential for a bubble forming at 30%.”
From MarketWatch ● Dec. 29, 2025
In the mountains east of San Diego, a wind gust of 102 mph was recorded at Sill Hill, nearing the all-time record of 105 mph recorded there on Feb. 26, 2020, Tardy said.
From Los Angeles Times ● Jan. 22, 2025
The piece is now the star-attraction in a new exhibition at The Sill visitor centre near Hexham, in Northumberland, which celebrates the life of the tree.
From BBC ● Sep. 28, 2024
“People don’t realize until after that the kayak doesn’t fit the space well,” Sill says.
From Seattle Times ● May 17, 2024
Known as Wally, she was a flight instructor at Fort Sill, an army base in southwestern Oklahoma, when she picked up the Life magazine featuring Jerrie Cobb.
From "Women in Space" by Karen Bush Gibson
She said the grills had worked as a deterrent, not only stopping drinkers from damaging her windows, but also preventing them from sitting on her window sills and putting their glasses on them.
From BBC ● Mar. 4, 2026
I have so many books, but never enough shelves, so I have books everywhere — piled up on tables, chairs, running along window sills, books in every available nook and cranny.
From New York Times ● May 9, 2024
Snow gently piled on window sills and in corners didn’t melt, revealing one piece of trivia most Hallmark aficionados have long known.
From Salon ● Dec. 23, 2023
Eventually, all that water poured into Planada, rushing into town in the dark, surrounding people’s homes, rising up in their yards, eventually seeping in under door frames and window sills.
From Los Angeles Times ● Dec. 18, 2023
On sills, on stoops, on crates and broken chairs they sat tasting their teeth and waiting for something to distract them.
From "Sula" by Toni Morrison
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.
