Sentence:  She fell asleep leaning on her hand , hearing the house creaking as though it were a living a private life of its own these two hundred years , hearing the birds rustling in their cages and the occasional whirring of wings as one of them landed on the table and walked across the newspaper to perch in the <WSD>crook</WSD> of her arm . 
Meaning of the word marked with <WSD> tags:  a circular segment of a curve