A double-entendre is a phrase or figure of speech that could have two meanings or that could be understood in two different ways.
There are many examples of double-entendre found in literature and in life. In fact, even William Shakespeare and Chaucer used double-entendres.
One of the earliest known examples of a double-entre found in literature dates back to the 14th century. In his famous work, The Canterbury Tales, Chaucer used many different examples of double-entendres. On of the most famous, however, is the use of the word "queynte" to describe both the domestic and womanly duties in the home as well as the female genitalia.
Double-entendre has been found in literature, movies and daily speech every since.
Some other examples of double-entendre include:
Because double-entendres are words or phrases that can be interpreted in two ways, they aren't always sexual in nature and sometimes they are not even intentional.
Some examples of accidental double-entendres that have been printed in newspapers or published on the Internet include:
Double-entendres, when used intentionally, can be fun and entertaining because the idea is to get a laugh both from people in the know and from people who do not get the second (or sexual) meaning.
These are just a few of many examples, as often movie and television producers today will use double-entendres so that shows and movies are both entertaining for kids (who do not get the second, sexual or tawdry reference) and for parents who do.