(误会) mistake: A wrong thought, act. It implies carelessness. Anyone can make a mistake.

　　(过错 弱点) fault: A bad point, but not of a serious moral kind. It refers to behavior and character. His only fault is that he lacks ambition.

　　find fault with sb / at fault

　　shortcoming: weakness, failing It refers to failures or deficiencies in things as well as people. In spite of all her shortcomings I still think she's one of the best teachers in the school.

　　(疏忽) error: A mistake (formal sometimes literary) It implies deviation from a standard or model

　　The accident was caused by human error.

　　(缺点 毛病) defect: sth lacking or imperfect. It refers to quality. The radio was returned because of a defect.

　　(失误 过失) blunder: A very stupid or unnecessary mistake. It implies ignorance. This is the fatal blunder of his life.