If you do something squintingly, you do it while looking with your eyes partly closed.
Squintingly can make people think of trying to see something far away or in bright light.
Examples:
She looked squintingly at the bright sun.
He read the sign squintingly because it was far away.
The children squintingly watched the bird in the sky.
He squintingly tried to read the tiny writing.
She squintingly peered into the distance, trying to see the ship.
The old man squintingly looked at the small letters on the page.