the symbol * , used to refer readers to a note at the bottom of a page of text, or to show that a letter is missing from a word

Sometimes taboo words are written with asterisks to avoid causing offence. 有时禁忌词中会用星号来代替某些字母，以避免冒犯读者。

something that makes an achievement less impressive or less complete

It's a new world record, but one with an asterisk. 这次世界纪录的告破并非是完美无瑕的。

to write an asterisk next to something

I have asterisked the books that are essential reading for the course. 我已将本课程的必读书目标上了星号。