Much Ado About Nothing is a double entendre on the word 'nothing'.

Breifly, the play deals with a woman, Hero, and her supposed adultery. At the end, she is absolved, and everything works out to everybody's advantage.

In Shakespearean times, 'nothing' was slang for a woman's genitals (As mens' genitals were 'something', therefore making womens' 'nothing).

Therefore.. Much Ado about Nothing.