Grille

All I can see through the window grille is part of a bare concrete wall.

Source: tatoeba (11063865)

Enervated but suddenly on adrenaline deer alert, our eyes the size of egg yolks, we crept onward at half the posted speed limit, certain that an amorous buck would come bounding out of the brush and into our grille.

Source: tatoeba (11204589)

The house was a big elaborate limestone affair, evidently new. Winter sunshine sparkled on lace-hung casement, on glass marquise, and the burnished bronze foliations of grille and door.

Source: wiktionary