Answer:
What English word retains the same pronunciation, even after you take away four of its five letters?
By Moon or by Sun, I shall be found. Yet I am undone, if there's no light around
It is worldwide, but once only a spider could weave one
Its title means book.
I build up castles. I tear down mountains. I make some men blind. I help others to see.
I am your mother's brother's only brother in law. Who am I?