mystery

mystery /ˈmɪstəri/ noun
plural mysteries
mystery
/ˈmɪstəri/
noun
plural mysteries
Britannica Dictionary definition of MYSTERY
1 
[count] : something that is not known
: something that is difficult to understand or explain
2 
[noncount] : the quality of being difficult to understand or explain : the quality of being mysterious
3 
[count] : a religious event or idea that cannot be fully understood or explained
4 
[count] : a book, play, or movie that describes a crime and the process of solving it
— often used before another noun
5 
[count] : someone or something whose identity has been kept secret especially in order to create interest or excitement — usually used before another noun