Vast1. (superl.) Waste; desert; desolate; lonely.
2. (superl.) of the vast ocean; vast mountains; the vast empire of Russia.
3. (superl.) Very great in numbers, quantity, or amount; as, a vast army; a vast sum of money.
4. (superl.) Very great in importance; as, a subject of vast concern.
5. (n.) A waste region; boundless space; immensity.
Thesaurus Entries
Atlantean, Brobdingnagian, Cyclopean, Gargantuan, Herculean, Homeric, abysmal, ample, amplitudinous, astronomic, astronomical, awesome, behemoth, big, boundless, broad, bulky, capacious, colossal, commodious, cosmic, deep, elephantine, endless, enormous, epic, expansive, extended, extending, extensive, far-flung, far-reaching, galactic, giant, giantlike, gigantic, great, heroic, huge, humongous, immeasurable, immense, incalculable, indeterminate, inexhaustible, infinite, interminable, jumbo, king-size, large, limitless, mammoth, massive, massy, measureless, mighty, monster, monstrous, monumental, mountainous, never-ending, outsize, overgrown, prodigious, profound, roomy, sizable, spacious, spreading, stupendous, titanic, towering, tremendous, unbounded, unlimited, voluminous, weighty, whopping, wide, widespread