irrational

Definition

Not rational; unfounded, nonsensical or wrong-headed.

Etymology

From Latin irratiōnālis, from ir- + ratiōnālis.

Example Sentences

• "an irrational decision"
• "July 18, 2012, Scott Tobias, AV Club The Dark Knight Riseshttp://www.avclub.com/articles/the-dark-knight-rises-review-batman,82624/ Where the Joker preys on our fears of random, irrational acts of terror, Bane has an all-consuming, dictatorial agenda that’s more stable and permanent, a New World Order that’s been planned out with the precision of a military coup."
• "The number π is irrational."