The Open Dictionary

windowsill

noun

UK/ˈwɪn.dəʊ.sɪl/
US/ˈwɪn.doʊ.sɪl/

Definitions of windowsill noun

  1. Countable

    A horizontal shelf or ledge located at the base of a window, either on the interior or exterior of a building.

    • She placed the cat on the windowsill so it could watch the activity outside.

    • I enjoy growing herbs on the windowsill.

    • During the winter, condensation often collects on the windowsill.