A double entendre (plural double entendres) is a figure of speech or a particular way of wording that is devised to have a double meaning, of which one is typically obvious, whereas the other often conveys a message that would be too socially awkward, sexually suggestive, or offensive to state directly. A double entendre may exploit puns or word play to convey the second meaning. Double entendres generally rely 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. Sometimes a homophone can be used as a pun. When three or more meanings have been constructed, this is known as a "triple entendre", etc. According to the Merriam-Webster Unabridged Dictionary and the Oxford English Dictionary, the expression comes from the rare and obsolete French expression, which literally meant "double meaning" and was used in the senses of "double understanding" or "ambiguity" but acquired its current suggestive twist in English after being first used in 1673 by John Dryden. The phrase has not been used in French for centuries and would be ungrammatical in modern French. No exact equivalent exists in French, whose similar expressions (mot/expression à) double entente and (mot/expression à) double sens do not have the suggestiveness of the English expression. A person who is unfamiliar with the hidden or alternative meaning of a sentence may fail to detect its innuendos, aside from observing that others find it humorous for no apparent reason. Innuendo is often used in sitcoms and other comedy where some in the audience may enjoy the humour while being oblivious to its secondary meaning. A triple entendre is a phrase that can be understood in any of three ways, such as in the back cover of the 1981 Rush album Moving Pictures which shows a moving company carrying paintings out of a building while people are shown being emotionally moved and a film crew makes a "moving picture" of the whole scene.