Englishillogical
adjective
he drew a strange and illogical conclusion:
irrational, unreasonable, unsound, unreasoned, unfounded, groundless, unjustifiable, unjustified;
incorrect, erroneous, wrong, invalid, spurious, faulty, flawed, fallacious, unscientific, inconsistent, unproved;
specious, sophistic, casuistic;
absurd, preposterous, untenable, implausible, impossible, beyond belief, beyond the bounds of possibility;
senseless, meaningless, nonsensical, insane, ridiculous, idiotic, stupid, foolish, silly, inane, imbecilic;
informal crazy, off beam, way out, full of holes;
British, informal daft, barmy;
North American, informal backasswards.
▷antonyms logical.
illogical Oxford Dictionary of English