Vast

a. [compar. VASTER; superl. VASTEST.] [Fr. vaste, Sp., Pg., & It. vasto, Lat. vastus, empty, waste, vast.]

1. Waste; desert; desolate; lonely. [Obs.] “The empty, vast, and wandering air.” Shak.
2. Being of great extent; very spacious or large; as, the vast ocean; a vast abyss; the vast empire of Russia; the vast plains of Syria. “Through the vast and boundless deep.” Milton.
3. Very great in numbers or amount; as, a vast army; vast numbers or multitudes were slain.
4. Very great in force; mighty; as, vast labor.
5. Very great in importance; as, a subject of vast concern.

Syn.—Enormous; huge; immense; mighty.