pleonasm

Pleonasm is redundancy in linguistic expression, such as "black darkness" or "burning fire". It is a manifestation of tautology by traditional rhetorical criteria and might be considered a fault of style. Pleonasm may also be used for emphasis, or because the phrase has become established in a certain form. Tautology and pleonasm are not consistently differentiated in literature. Usage Most often, pleonasm is understood to mean a word or phrase which is useless, clichéd, or repetitive, but a pleonasm can also be simply an unremarkable use of idiom. It can aid in achieving a specific linguistic effect, be it social, poetic or literary. Pleonasm sometimes serves the same function as rhetorical repetition—it can be used to reinforce an idea, contention or question, rendering writing clearer and easier to understand. Pleonasm can serve as a redundancy check; if a word is unknown, misunderstood, misheard, or if the medium of communication is poor—a static-filled radio transmission or sloppy handwriting—pleonastic phrases can help ensure that the meaning is communicated even if some of the words are lost. Idiomatic expressions Some pleonastic phrases are part of a language's idiom, like tuna fish, chain mail and safe haven in American English. They are so common that their use is unremarkable and often even unnoticeable for native speakers, although in many cases the redundancy can be dropped with no loss of meaning. When expressing possibility, English speakers often use potentially pleonastic expressions such as It might be possible or perhaps it's possible, where both terms (verb might or adverb perhaps along with the adjective possible) have the same meaning under certain constructions. Many speakers of English use such expressions for possibility in general, such that most instances of such expressions by those speakers are in fact pleonastic. Others, however, use this expression only to indicate a distinction between ontological possibility and epistemic possibility, as in "Both the ontological possibility of X under current conditions and the ontological impossibility of X under current conditions are epistemically possible" (in logical terms, "I am not aware of any facts inconsistent with the truth of proposition X, but I am likewise not aware of any facts inconsistent with the truth of the negation of X").