irrational
adjective uk/ɪˈræʃ.ən.əl/ us/ɪˈræʃ.ən.əl/
C2 不理智的，没有理性的
not using reason or clear thinking
It's totally irrational, but I'm frightened of mice. 这很荒唐，但我的确害怕老鼠。
His parents were worried by his increasingly irrational behaviour. 他的父母因他的行为越来越乖僻而担忧。