A
double entendre or
adianoeta[1] is a
figure of speech in which a spoken
phrase is devised to be understood in either of two ways. Often the first meaning is straightforward, while the second meaning is less so; often
risqué, inappropriate, or
ironic.
The Oxford English Dictionary defines a double entendre as especially being used to "convey an indelicate meaning". It is often used to express potentially offensive opinions without the risks of explicitly doing so.
A double entendre may exploit puns to convey the second meaning, but puns are more often used in sentences that do not have a second meaning. Double entendres tend to rely more on multiple meanings of words, or different interpretations of the same primary meaning; they often exploit ambiguity and may be used to introduce it deliberately in a text.
In some double entendres, the second meaning may require replacing an "innocent" word by a completely dissimilar "risqué" one, this "key" being suggested only by the context, or by the altered sentence being known to the audience.