A double entendre is a figure of speech or a particular way of wording that is devised to be understood in either of two ways, having a double meaning. Typically one of the meanings is obvious, given the context whereas the other may require more thought.
Definition of double entendre
A double entendre is a phrase that has more than one meaning, or can be interpreted in multiple ways. Usually, one of the meanings of the double entendre is obvious, whereas the other one is more hidden.
The user of a double entendre can thus often imply the second meaning, while nevertheless maintaining a kind of plausible deniability: if someone calls him out on the second meaning, he could always say that he never meant anything like that.
The double entendre is thus always characterized by ambiguity. This ambiguity can often be leveraged for comedic or dramatic effect.
Two main types
In general, there are two main kinds of the double entendre. The first usually consists of sexual innuendo and/or some other form of impolite remark: the double entendre is formulated to consciously mask the intended meaning with a more innocent surface meaning. The other kind of double entendre is formulated by accident as a result of a poor usage of language.
An example of the first kind of double entendre could be something as simple as the statement:
"I had a really fun time with her last night."
On the one hand, this could simply mean what it self-evidently says: it is a description of the emotional state of the speaker. On the other, though, depending on the tone and context of the statement, it could be meant to imply a sexual encounter. The double entendre would thus allow the speaker to be somewhat discreet in talking about that experience.
An example of a real headline that is an unintended double entendre is the following:
"Panda mating fails; veterinarian takes over".
This statement is clearly intended to mean that the veterinarian helped the pandas mate in some way. The poor use of language, though, implies the second meaning that the veterinarian himself mated with a panda.
Relation to literature
The double entendre is closely connected with the concepts of innuendo and irony (rhetorical devices). By using the double entendre in an effective way, the speaker can introduce ambiguity into a social situation and say something while nevertheless denying that he is saying it. For example, the double entendre plays a huge role in the practice of flirting. A man may want to express interest in a woman, but he knows that it would be too lewd to say so outright; so, he uses a double entendre in order to say it and not say it at the same time.
In this sense, the double entendre can offer the speaker a kind of social protection, since he can always deny the more hidden or implicit meaning of his statement. It can also be used effectively for humorous purposes and for establishing a line between an in-crowd and an out-crowd. For example, some people may understand the hidden meaning of a given double entendre, whereas others may be oblivious to it and thus mistake the double entendre for a simple statement. This can be funny both because of the sense of getting the joke as well as the sense of understanding something that others don't.