Synonyms:
- baseless,
- bottomless,
- built on sand,
- chimerical,
- empty,
- flimsy,
- gratuitous,
- hypothetical,
- idle,
- ill-founded,
- illusory,
- imaginary,
- inconclusive,
- indecisive,
- not following,
- not proved,
- not well-founded,
- speculative,
- suppositional,
- tenuous,
- unascertained,
- unattested,
- unauthenticated,
- unbased,
- uncalled-for,
- uncertified,
- unconfirmed,
- uncorroborated,
- undemonstrated,
- undetermined,
- unestablished,
- unfixed,
- unfounded,
- ungrounded,
- unjustifiable,
- unjustified,
- unproved,
- unproven,
- unreasonable,
- unsettled,
- unshown,
- unsound,
- unsubstantiated,
- unsupportable,
- unsupported,
- unsupported by evidence,
- unsustainable,
- unsustained,
- untenable,
- untested,
- untried,
- unvalidated,
- unverified,
- unwarranted,
- vain,
- without basis,
- without foundation,
- without grounds