Window-sill

There was a glass of water on the table, and on the window-sill a small chip ointment box containing a couple of pills.

Source: tatoeba (6310144)

Tom leaned on the window-sill.

Source: tatoeba (6851736)

Horned toads hopped about; each of the four upper corners of the room was festooned with a thick cobweb, in the center of which sat a spider as big around as a washbasin, and armed with pincher-like claws; a red-and-green lizard was stretched at full length on the window-sill and black rats darted in and out of the holes they had gnawed in the floor of the cottage.

Source: tatoeba (11805656)

After amusing herself for a brief time with picking to pieces some mignonette which filled a box on the window-sill, Marie threw the flowers from her, and exclaimed,—"And here we are seated together, as we used to talk away half the night in Italy. Good Heavens! how we are altered!"

Source: wiktionary