A catch or locking-device for holding a window-sash open or shut.(noun)
The Century Dictionary (Public Domain)
Use "window-latch" in a sentence
"That was the style of the letter, and it ended by imploring me to leave the window-latch open, and to be in the front room at three in the morning, when he would come to receive my last kiss and to bid me farewell."
"That was Mr. Brunger's discovery after examination of the window-latch where George's knife had marked it, the sill where George's boots had scratched it."
"The window-latch is firm, the curtain does not tremble,"