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 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
They’re sill exploring options, including possibly lending it to the L.A.
From Los Angeles Times ● Mar. 11, 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
Natalie grabbed the sill of the high window from the outside and pulled herself up—easier now that the water was higher—and saw her mother’s frightened face.
From "Two Degrees" by Alan Gratz
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
Sill says people always reach out with funny questions about what exactly they can store.
From Seattle Times ● May 17, 2024
The recollections will be added to a temporary exhibition at The Sill, Northumberland National Park Authority's visitor hub.
From BBC ● Dec. 6, 2023
Soon after this I was sent once more to Fort Sill, Oklahoma, for still more missile and radar schooling.
From This Side of Wild by Gary Paulsen
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
Eventually the window sills were completely done—two coats—and my mother had Nathan start on the wood railing of our front porch.
From "It All Comes Down to This" by Karen English
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.
