Vast :: Vast (superl.) Of great extent; very spacious or large; also, huge in bulk; immense; enormous; as, the vast ocean; vast mountains; the vast empire of Russia..
Vast :: Vast (superl.) Very great in numbers, quantity, or amount; as, a vast army; a vast sum of money..
Vast :: Vast (superl.) Very great in importance; as, a subject of vast concern..
Vast :: Vast (n.) A waste region; boundless space; immensity.
Vastation :: Vastation (n.) A laying waste; waste; depopulation; devastation.