As a Noun: 1. Behaviour which is foolish, silly or strange. English = foolishness, idiocy, craziness, stupidity. 2. A person whose behaviour is foolish, silly or strange. English = fool, idiot, madman. Informal English = loony. 3. Something written or said that you think is untrue, foolish or stupid. English = nonsense. As a Verb or Adjective: 1. To say or do things which are foolish, silly or strange. English = (be) mad, (be) stupid, (be) crazy, (be) idiotic. Informal English = (be) loony. 2. To fool or take advantage of someone. Interactive: 1. Used alone to mean that you think what someone has said is untrue, stupid or foolish. English = 'Nonsense!', 'Rubbish!'