asterisk          
 noun [ C ] uk/ˈæs.tər.ɪsk/ us/ˈæs.tɚ.ɪsk/
 (表示下有注释或单词中字母的缺失的)星号(*)
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。 
  US侥幸|瑕疵|缺憾 
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。 
 - More examples
 - Use an asterisk to represent any letter you do not know.
 - Where is the asterisk on this keyboard?
 - The sections are divided with a line of asterisks.
 
asterisk       
verb [ T ] uk/ˈæs.tər.ɪsk/ us/ˈæs.tɚ.ɪsk/
 加星号于
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。