Sentence:  "The elements of a list are the successive cars along the "<WSD>cdr</WSD> chain." That is, the elements are the car, the car of the <WSD>cdr</WSD>, the car of the <WSD>cdr</WSD> of the <WSD>cdr</WSD>, etc." 
Meaning of the word marked with <WSD> tags:  The second part of a cons in LISP. The rest of a list when the first element is removed.