From Longman Dictionary of Contemporary Englishwindowpanewin‧dow‧pane /ˈwɪndəʊpeɪn $ -doʊ-/ noun [countable] DHa single whole piece of glass in a window
Examples from the Corpus
windowpane• A trace of early-morning red showed on a fifth-floor windowpane.• The last breath of a dying wind rattled the kitchen windowpane.• The real sky, outside, is a black mirror pushed right up against the windowpanes.• Overnight all the windowpanes had been frosted over.• More rain hit the windowpanes, and Leith came to a decision.• He went to sleep as he stood there, clutching his glass, his forehead resting on the windowpane.• The first cold winds rattled the windowpane, and I had made it just in time.• There was not one unbroken windowpane.