Sentence:  Nanny Broome was looking up at the outer wall. Just under the ceiling there were three lunette windows, heavily barred and blacked out in the normal way by centuries of grime. Their bases were on a <WSD>level</WSD> with the pavement outside, a narrow way which was several feet lower than the road behind the house. 
Meaning of the word marked with <WSD> tags:  At the same height as some reference; constructed as "level with".