lunatic

a person who is mentally ill, especially one who behaves in a violent or dangerous way

locura, demente, lunático

Collocations lunatic asylum

• The police had to take him away because he was a danger to others.

  La policía tuvo que llevárselo porque era un peligro para los demás.

behavior that is very strange or unreasonable, as if someone has lost their mind

locura, comportamiento extraño, actitud absurda

Collocations lunatic behavior

• His actions were completely lunatic.

  Sus acciones fueron completamente absurdas.