rhizoverbBeta
DictionarymentalIrrational or wildly unusual
adjective

mental

Wildly irrational or unusual, in informal and sometimes offensive use.

Trying to cross that flooded road on foot is mental.

Etymology
mentLatinmind
+alEnglishrelating to

Mental originally describes things relating to the mind. The slang sense developed by narrowing this association to mental disturbance, then broadening it to extreme or irrational behavior.

More examples

  • You must be mental to swim here during a thunderstorm.
  • The prices at that hotel are absolutely mental.
  • This whole plan sounds mental, but it might actually work.

Forms

mental

Similar words

crazy
Similarly informal and potentially offensive; also expresses enthusiasm or excitement.
bizarre
Emphasizes extreme strangeness rather than irrational thought or behavior.
unhinged
Suggests a loss of emotional control, not just unusualness.