What is the meaning of Sill?

A breast wall; window breast; horizontal brink which forms the base of a window.

A threshold; horizontal structural member of a building near ground level on a foundation or pilings, or lying on the ground, and bearing the upright portion of a frame; a sill plate.

A stratum of rock, especially an intrusive layer of igneous rock lying parallel to surrounding strata.

A threshold or brink across the bottom of a canal lock for the gates to shut against.

A raised area at the base of the nasal aperture in the skull.

The inner edge of the bottom of an embrasure.

A young herring.

The shaft or thill of a carriage.

Silly.

sill

herring

Alternative form of sillaf (syllable)

Source: wiktionary.org