windowsill

or win·dow sill

[ win-doh-sil ]
/ ˈwɪn doʊˌsɪl /

noun

the sill under a window.

Origin of windowsill

First recorded in 1695–1705; window + sill
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for windowsill

British Dictionary definitions for windowsill

windowsill

/ (ˈwɪndəʊˌsɪl) /

noun

a sill below a window
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012