ill-founded

Lacking solid ground

Ill-founded means lacking a solid basis in fact or reason: ill-founded rumors, ill-founded fears.

The term suggests that something—a belief, accusation, or concern—rests on weak evidence or faulty logic.

His optimism proved ill-founded when the deal collapsed.

epistemic

baseless

Lacking factual support

unsubstantiatedWithout supporting evidence
groundlessLacking factual support
unsupportedLacking backing or proof

unwarranted · unjustified · speculative · flimsy · spurious · dubious · questionable · tenuous · weak · shaky

assertions

claims

Statements of truth

allegationsUnproven formal claims
accusationsClaims of fault
assumptionsUnproven things taken as true

beliefs · opinions · rumors · gossip · hearsay · speculation · conjecture · theories · hypotheses · assertions

emotional

fears

Feelings of dread

suspicionsBeliefs without full proof
anxietiesPersistent mental unease
worriesPersistent mental unease

doubts · paranoia · jealousy · distrust · apprehension · misgivings · insecurities · panic · dread · phobia

Opposites

evidential basis

ill-foundedwell-founded

Having sound basis

well-grounded · founded · grounded · substantiated · evidence-based

reasoning quality

ill-foundedsound

Audible wave phenomenon

logical · rational · cogent · valid · justified

justification strength

ill-foundedjustified

Shown to be right

warranted · legitimate · reasonable · defensible · tenable

Family

found, foundation, foundations, unfounded, foundational, foundationless, refounded

Familiarity: Top 200,000
Profile: Used worldwide · Timeless · Abstract · Negative · Everyday, not technical · Rated G