Meaning & Definition
adjective
Not observing the principles of logic; not reasonable or rational.
His argument was dismissed as illogical because it was based on faulty assumptions.
Characterized by a lack of clear, sound reasoning.
Trying to justify such an illogical decision only added to the confusion.
Contrary to the dictates of reason; absurd.
It seems illogical to spend money on a new car when you can barely afford your current expenses.
Difficult to understand due to incoherence or contradictions.
The illogical flow of the presentation left the audience puzzled.
Etymology
From the prefix 'il-' meaning 'not' + 'logical', from Greek 'logikos'.
Common Phrases and Expressions
illogical reasoning:
reasoning that fails to follow principles of logic
illogical conclusion:
a conclusion drawn that lacks rational basis
Slang Meanings
crazy idea
That's such an illogical thing to say; are you out of your mind?
makes no sense
Trying to justify that is just illogical, dude!