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

The Environmental Protection Agency warns parents of young children living in older homes to be aware of high-use areas such as window sills, doors, door frames, stairs, railings, banisters and porches. —Ken Alltucker, USA TODAY, 5 Dec. 2024

Designers traded in most of the base car’s straight, simple panels for bulging, muscular ones and affixed all sorts of aerodynamically minded pieces — splitter, spoiler, side sills — to slash drag and add confidence at high speed. —Will Sabel Courtney, Robb Report, 3 Dec. 2024

The Pinal County Sheriff's Office said the incident is sill under investigation. —Kimberlee Speakman, People.com, 1 Nov. 2024

However, cleaning the dirt and grim on the exterior glass, frame, and sill can make your home’s exterior look much better. —Terri Williams, Forbes, 17 Sep. 2024

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

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