Oh, what a lovely question! A 4-letter word meaning something you sit on is a "seat." Just imagine a cozy seat where you can relax and enjoy the beauty around you. Take a moment to appreciate the simple things in life, like a comfortable seat to rest upon.
Seat.
seat
seat
Something you sit on that begins with K is your kiester.
House is the English meaning for the Kikuyu word Nyumba.
Something that you sit on add one letter to kit
katse-kat katse meaning sit and kato meaning down
Sanhedrin
kate
The word "cancel" is the opposite of sit, in the sense of convene.
Birds sit on a nest. It begins with the letter n.
A Yacht!