vastest
Largest in scope
Vastest is the superlative form of vast—the most extensive or immense: the vastest ocean, the vastest empire the world had ever seen.
The word is grammatically correct but somewhat awkward; many writers prefer most vast or restructure to avoid the superlative entirely.
Extremely large in scale
- giganticImmensely large in scale
- enormousExtremely large in scale
- tremendousExtraordinarily large or powerful
- massiveExtremely large and heavy
gargantuan · titanic · mammoth · immense · prodigious · stupendous · astronomical · monumental
Without any boundaries
- unlimitedWithout bounds or restrictions
- infiniteHaving no bounds
- endlessWithout termination or boundary
- unboundedHaving no limits
measureless · unrestricted · unconfined · inexhaustible · unfettered · unconstrained · open-ended · fathomless
colossal
Extremely large in scale
- giganticImmensely large in scale
- enormousExtremely large in scale
- tremendousExtraordinarily large or powerful
massive · gargantuan · titanic · mammoth · immense · prodigious · stupendous · astronomical · monumental · epic
limitless
Without any boundaries
- unlimitedWithout bounds or restrictions
- infiniteHaving no bounds
- endlessWithout termination or boundary
unbounded · measureless · unrestricted · unconfined · inexhaustible · unfettered · unconstrained · open-ended · fathomless · bottomless
expanse
Unbroken area of space
breadth · extent · scope · range · prairie · savannah · steppe · tundra · plateau · terrain
eternal
Lasting without end
- perpetualLasting without interruption
- everlastingLasting for all time
- timelessUnaffected by eras
ageless · unending · unceasing · perennial · immortal · enduring · eons · millennia · epochs · ages