Doorsill Definition

dôrsĭl
noun
A length of wood, masonry, etc. along the bottom of a doorway; threshold.
Webster's New World

The horizontal piece of wood, stone or metal at the threshold of a doorway; a doorstep.

Wiktionary
Synonyms:

Other Word Forms of Doorsill

Noun

Singular:
doorsill
Plural:
doorsills