well-founded Antonyms

lift doesn't go all the way to the top unfounded unbacked stupid silly ridiculous rabid nonsensical mad lunatic loony unreasonable unsound weak devoid of substance unsubstantiated not right in the head dippy dim-witted cray cray coocoo coo-coo away with the fairies nonrational irrational insane inconsequential cray crayfish careless brash brainsick brainless blunt baseless asinine absurd crazed crazy cuckoo inconsequent illogical idiotic groundless foolish eristic dim deranged demented daft