The most prominent example of an idiom in the play is in the title itself: Much Ado About Nothing. This phrase refers to a great fuss over something trivial. In the context of the play, this title can be read in a variety of ways, based on how the word "nothing" is interpreted.
Firstly, the idiom might be read as "much ado about nothing"—that is, "much ado about" matters of no importance. In the context of the play, these matters of no importance could refer to the false allegations of infidelity against Hero, which are revealed to be fabricated and thus amount to "nothing." These matters might also refer to romance, which seems trivial or unimportant compared to the world of war from which the soldiers have recently returned.
Secondly, "nothing" might be read as a euphemism for female genitalia, since the word was sometimes used as such in Shakespeare's time (the joke at the time being that women had "no thing" between their legs). According to this interpretation, the title refers to the fact that a lot of fuss is made in the play over women's bodies and sexuality.
Finally, the title might be read as "much ado about noting,"a homonym for "nothing" in Shakespeare's day. This reading also rings true: false or distorted perceptions of reality generate a great deal of commotion in the play. In this way, the idiom in the title of the play cleverly refracts Shakespeare's themes concerning romance, sexuality, and perception.
