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

Like the vehicle’s scoops and spoilers, the dihedral doors don’t simply look dramatic but are purposeful in design, in this case aiding access by incorporating sections of the roof and sill. —Tim Pitt, Robb Report, 9 Apr. 2025

Honda For its part, Honda sells the detachable tow bar, floor mats, illuminated side sill garnishes, Thule rear bicycle carrier and side window sunshades as CR-V add-ons. —New Atlas, 11 Apr. 2025

Inside, the High Top Honcho sports tan-and-black leather seats, a bright pedal kit, and door sill guards. —Kristin Shaw, Forbes.com, 11 Apr. 2025

Carpet Cargo mat, illuminated door sills and roof racks were also good additions. —Marc D Grasso, Hartford Courant, 29 Mar. 2025

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