THESAURUS
baseless
bottomless, built on sand, empty, false, gratuitous, groundless, idle, ill-founded, indefensible, needless, not well-founded, pointless, reasonless, senseless, unbased, uncalled-for, unfounded, ungrounded, unjustifiable, unnecessary, unneeded, unsolid, unsupportable, unsupported, unsustainable, unsustained, untenable, unwarranted, vain, without basis, without foundation, wrong
ROGET THESAURUS
baseless
Inexistence
N
inexistence, nonexistence, nonsubsistence, nonentity, nil, negativeness, nullity, nihility, nihilism, tabula rasa, blank, abeyance, absence, no such thing, nonbeing, nothingness, oblivion, annihilation, extinction, extinguishment, extirpation, Nirvana, obliteration, inexistent, nonexistent, negative, blank, missing, omitted, absent, insubstantial, shadowy, spectral, visionary, unreal, potential, virtual,
baseless, in nubibus, unsubstantial, vain, unborn, uncreated, unbegotten, unconceived, unproduced, unmade, perished, annihilated extinct, exhausted, gone, lost, vanished, departed, gone with the wind, defunct, fabulous, ideal, supposititious &c, negatively, virtually, non ens.
Unsubstantiality
N
unsubstantiality, insubstantiality, nothingness, nihility, no degree, no part, no quantity, no thing, nothing, naught, nil, nullity, zero, cipher, no one, nobody, never a one, ne'er a one, no such thing, none in the world, nothing whatever, nothing at all, nothing on earth, not a particle, all talk, moonshine, stuff and nonsense, matter of no importance, matter of no consequence, thing of naught, man of straw, John Doe and Richard Roe, faggot voter, nominis umbra, nonentity, flash in the pan, vox et praeterea nihil, shadow, phantom, dream, ignis fatuus, such stuff as dreams are made of, air, thin air, vapor, bubble,
baseless fabric of a vision, mockery, hollowness, blank, void, inanity, fool's paradise, unsubstantial,
baseless, groundless, ungrounded, without foundation, having no foundation, visionary, immaterial, spectral, dreamy, shadowy, ethereal, airy, cloud built, cloud formed, gossamery, illusory, insubstantial, unreal, vacant, vacuous, empty, eviscerated, blank, hollow, nominal, null, inane, there's nothing in it, an ocean of dreams without a sound.