The phrase "a side window" is correct and usable in written English.
It can be used to refer to a window located on the side of a structure, vehicle, or object.
Example: "The car had a side window that was slightly cracked, allowing a breeze to enter the vehicle."
Alternatives: "a lateral window" or "a flank window".
A side window was closed but unlocked.
Cuddy was thrown out a side window and suffered a traumatic brain injury.
Back on the road, a side window fell into the lap of a startled Juan Carlos.
Officer Turner forced open the front door, and Officer Hatzel broke through a side window.
After an initial burst of fire they dragged Bhatti's driver from the vehicle, then continued firing through a side window.
She said chunks of concrete shattered the front windshield, broke a side window and narrowly missed one technician's head.
One day in the auto-parts store, where Carol Match was checking to see if her order for a side-window sunscreen for the restored 1948 Chevy half-ton had come in, he listened to her talking to Chet Breen behind the counter.
Photocatalytic hydrogen evolution was performed in a side-window reaction cell.
The average molecule contained in each pixel is displayed on a side-window on mouse over, with an option to open the complete list of molecules in the pixel in a secondary window, and subsequently to link selected molecules to the database entry, or to perform similarity searches in the parent high-dimensional property space.
Digital luminometer (BioOrbit 1250, Turku, Finland) equipped with a side-window type photomultiplier tube with a dynamic range up to 6 decades and a sensitivity of 0.05 fmoles of ATP per assay.
A bullet pierced a tinted side window of Ms. Land's black Pontiac Grand Prix, slicing through her neck and lodging behind her shoulder.
