irrational

ir·ra·tio·nal

adj \(ˈ)ir-ˈ(r)ash-nəl, -ən-^əl\

Definition of IRRATIONAL

: not rational: as a : lacking usual or normal mental clarity or coherence <was irrational for several days after the accident> b : not governed by or according to reason <irrational fears>

—ir·ra·tio·nal·i·ty \(ˌ)ir-ˌ(r)ash-ə-ˈnal-ət-ē\ (audio pronunciation) noun, plural ; ir·ra·tio·nal·i·ties

—ir·ra·tio·nal·ly \(ˈ)ir-ˈ(r)ash-nə-lē, -ən-^əl-ē\ (audio pronunciation) adverb