a mental state where somebody becomes excited and not able to think or speak clearly, usually because of illness 谵妄，神志失常，说胡话（常由疾病引起） fits of delirium 一阵阵胡言乱语 He mumbled in delirium all night. 他整晚都在狂妄地喃喃自灭。
Word Originmid 16th cent.: from Latin, from delirare ‘deviate, be deranged’ (literally ‘deviate from the furrow’), from de- ‘away’ + lira ‘ridge between furrows’.