Vast(n.) A waste region; boundless space; immensity.
Vast(superl.) Waste; desert; desolate; lonely.
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(superl.) Very great in numbers, quantity, or amount; as, a vast army; a vast sum of money.
Vast(superl.) Very great in importance; as, a subject of vast concern.
Vastly(adv.) To a vast extent or degree; very greatly; immensely.
Vastness(n.) The quality or state of being vast.
Words within vastnesses