Lacking sense or clear, sound reasoning.

असंगत

English Usage: The illogical decision led to unforeseen consequences.

Hindi Usage: असंगत निर्णय ने अप्रत्याशित परिणामों की ओर ले जाया।

Not based on or justified by reason.

तर्कहीन

English Usage: His unreasoned fears kept him from taking the necessary risks.

Hindi Usage: उसकी तर्कहीन चिंताओं ने उसे आवश्यक जोखिम उठाने से रोक दिया।