Sentence:  In 1908 the line was extended to a station called Wood Lane, which was built on a terminal track <WSD>loop</WSD> so that trains could turn round and go back the other way, [...] 
Meaning of the word marked with <WSD> tags:  A place at a terminus where trains or trams can turn round and go back the other way without having to reverse; a (balloon loop), turning loop, or reversing loop.