大意失荆州

大意失荆州:

Literally means:

suffer a major setback due to carelessness.

Actually means:

大意 means being careless; Jinzhou was an ancient Province. The phrase originally means that Guan Yu, a famous general of the Three Kingdoms (A. D. 222-280) in the Chinese history, was so careless in the defense of Jingzhou that he eventually lost the city to the enemy.

It figuratively means causing great loss due to one's carelessness. It is often used to remind people not to be arrogant or not to underestimate the enemy.

Sometimes it may also be used to justify one's own mistakes. It carries a sense of derogatory.

大意，不小心。荆州，现今湖北省的江陵。大意失荆州，指三国的大将关羽轻视敌人，不注意防守，以致丢失了荆州。

比喻麻痹大意，造成重大损失。多用来提醒别人不要骄傲自大对敌人估计不足。有时也用来对自己的失误辩解。具有贬义色彩。