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

Place them on bookshelves, window sills, mantels, and even in your fireplace to create a unique focal point in a room. —Claire Hoppe Norgaard, Better Homes & Gardens, 15 Oct. 2025

Use the wand to reach window sills and curtains, and opt for the pet multi-tool to lift pet hair from stairs and upholstered furniture. —Isabel Garcia, PEOPLE, 8 Oct. 2025

Dust the sills and tops of sashes. —Brandee Gruener, Southern Living, 3 Oct. 2025

The roof was tile and so were the window sills. —Literary Hub, 29 Sep. 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