This was Gollum's final riddle from The Hobbit:
"This thing all things devours;
Bird, beasts, trees, flowers;
Gnaws iron, bites steel;
Grinds hard stones to meal;
Slay king, ruins town,
and beats a mountain down."
It can't be seen, can't be felt, can't be heard and can't be smelt. It lies behind stars and under hills, and empty holes it fills. It comes first and follows after, ends life and kills laughter. What is it?
"You will hang me."
Since they cannot hang him - that will make him true and they can only hang him for a lie, and they cannot shoot him - they would mean he told the truth but if they shoot him it's a lie - he is free to go.
What word in the English language does the following: The first two letters signify a male, the first three letters signify a female, the first four letters signify a great man, while the entire word signifies a great woman. What is the word?