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 new New York Street was made to look like the city in the mid 20th century, a decision that required detailed craftsmanship such as window heads and sills that would have been carved out of wood in years past but were instead fabricated out of plastic foam and finished with plaster. —Roger Vincent, Los Angeles Times, 17 May 2024

To charge crystals using moonlight, simply place them outside or on a window sill where they can be exposed directly to moonlight. —Valerie Mesa, Peoplemag, 14 May 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