sill

noun

ˈsil 

1

: a horizontal piece (such as a timber) that forms the lowest member or one of the lowest members of a framework or supporting structure: such as

a

: the horizontal member at the base of a window

b

: the threshold of a door

2

: a tabular body of igneous rock injected while molten between sedimentary or volcanic beds or along foliation planes of metamorphic rocks

3

: a submerged ridge at relatively shallow depth separating the basins of two bodies of water

Examples of sill in a Sentence

Recent Examples on the Web

Black extensions adorn door sills. —Lawrence Ulrich, Robb Report, 12 June 2026

Use a microfiber cloth or duster to remove cobwebs and any visible soil around the window frame and sill. —Mary Marlowe Leverette, The Spruce, 12 June 2026

Guests re-create scenes for social media, posing under the geometric portico, at window sills, in elevators or on the side of the bed in the custom Masaru Mineo yukata (a light Japanese robe). —Carrie Bell, Forbes.com, 11 June 2026

The interiors, updated by a past owner, didn’t gel with her own taste, but the original bones still wowed, especially the dynamic rooflines, internal masonry walls, and chunky marble accents like lintels and sills. —Sam Cochran, Architectural Digest, 22 May 2026

Word History

Etymology

Middle English sille, from Old English syll; akin to Old High German swelli beam, threshold

First Known Use

before the 12th century, in the meaning defined at sense 1

Rhymes for sill

• bill
• brill
• chill
• drill
• fil
• fill
• frill
• gill
• grill
• grille
• jill
• kill

Kids Definition

sill

noun

ˈsil 

1

: a horizontal piece (as a timber) that forms the lowest part of a supporting structure: as

a

: the horizontal piece at the base of a window

b

: the timber or stone at the foot of a door : threshold

2

: a flat mass of igneous rock injected while melted between other rocks