1. 不可触动的；不受影响的；碰不得的
If you say that someone is untouchable, you mean that they cannot be affected or punished in any way.

2. 高人一等的；无与伦比的；无可匹敌的
If you describe someone, especially a sports player or entertainer, as untouchable, you are emphasizing that they are better than anyone else in what they do.

3. 不可接触者，贱民（指印度社会最低阶层的人）
Some people refer to Hindus of the lowest social rank as untouchables .