Irrational(adjective)
(Devoid of reason, not logical or reasonable.)
Hindi meaning:तर्कहीन
Synonyms: Unreasonable, Illogical, Groundless, Baseless, Unfounded, Unjustifiable
Example: Arachnophobia is known as an irrational fear of spiders.
Trick to remember: Ration nhi dene pe Irrational bate btate hai. 
