An idiom is a phrase or expression that typically presents a figurative, non-literal meaning attached to the phrase; but some phrases become figurative idioms while retaining the literal meaning of the phrase. Categorized as formulaic language, an idiom's figurative meaning is different from the literal meaning. Idioms occur frequently in all languages; in English alone there are an estimated twenty-five million idiomatic expressions. Derivations Many idiomatic expressions were meant literally in their original use, but sometimes the attribution of the literal meaning changed and the phrase itself grew away from its original roots—typically leading to a folk etymology. For instance, the phrase "spill the beans" (meaning to reveal a secret) is first attested in 1919, but has been said to originate from an ancient method of voting by depositing beans in jars, which could be spilled, prematurely revealing the results. Other idioms are deliberately figurative. For example, "break a leg" is an ironic expression to wish a person good luck just prior to their giving a performance or presentation. It may have arisen from the superstition that one ought not utter the words "good luck" to an actor because it is believed that doing so will cause the opposite result. Compositionality In linguistics, idioms are usually presumed to be figures of speech contradicting the principle of compositionality. That compositionality is the key notion for the analysis of idioms is emphasized in most accounts of idioms. This principle states that the meaning of a whole should be constructed from the meanings of the parts that make up the whole. In other words, one should be in a position to understand the whole if one understands the meanings of each of the parts that make up the whole. The following example is widely employed to illustrate the point: Understood compositionally, Fred has literally kicked an actual, physical bucket. The much more likely idiomatic reading, however, is non-compositional: Fred is understood to have died. Arriving at the idiomatic reading from the literal reading is unlikely for most speakers. What this means is that the idiomatic reading is, rather, stored as a single lexical item that is now largely independent of the literal reading. In phraseology, idioms are defined as a sub-type of phraseme, the meaning of which is not the regular sum of the meanings of its component parts. John Saeed defines an idiom as collocated words that became affixed to each other