Question

Where is the Lord Mayor of London?

(Why is 'Lord' added before 'Mayor'here? In the sentence, what is the meaning of 'Lord'?)
Writeacher
It's just his title. Some are referred to as simply the mayor, but in some very large cities (especially London and Dublin), the person who holds that office is referred to with that title.

http://en.wikipedia.org/wiki/Lord_Mayor_of_London