• (British) enPR: väst, IPA: /vɑːst/
• (America) IPA: /væst/

vast (comparative vaster, superlative vastest)

1. Very large or wide (literally or figuratively).

   The Sahara desert is vast.

   There is a vast difference between them.

2. Very great in size, amount, degree, intensity, or especially extent.
   • 1658, Thomas Browne, “The Garden of Cyrus. […]. Chapter III.”, in Hydriotaphia, Urne-buriall, […] Together with The Garden of Cyrus, […], London: Printed for Hen[ry] Brome […], OCLC 48702491 ↗; reprinted as Hydriotaphia (The English Replicas), New York, N.Y.: Payson & Clarke Ltd., 1927, OCLC 78413388 ↗, page 136 ↗:

     The exiguity and ſmallneſſe of ſome ſeeds extending to large productions is one of the magnalities of nature, ſomewhat illuſtrating the work of the Creation, and vaſt production from nothing.

3. (obsolete) Waste; desert; desolate; lonely.
   • c. 1593, William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act 1, scene 4]:

     the empty, vast, and wandering air

• French: vaste, immense
• German: beträchtlich, weit
• Italian: ampio, vasto, esteso
• Portuguese: vasto
• Russian: обши́рный
• Spanish: vasto

vast (plural vasts)

1. (poetic) A vast space.
   • 1608, William Shakespeare, The Winter's Tale, I.i

     they have seemed to be together, though absent, shook hands, as over a vast, and embraced, as it were, from the ends of opposed winds.

vast (plural vasts)

1. Acronym of visual audio sensory theater
2. (ESA, volcanology) Acronym of volcanic ash strategic initiative team