Sentence:  But after the doctor 's return that night Alex could see , from the high <WSD>window</WSD> in his own room , the now familiar figure crouched on a truly impressive heap of towels , apparently giving its egg hatching powers one final chance before it was replaced in its office by a sure-enough hen . 
Meaning of the word marked with <WSD> tags:  a framework of wood or metal that contains a glass windowpane and is built into a wall or roof to admit light or air