1 radically distinctive and without equal; "he is alone in the field of microbiology"; "this theory is altogether alone in its penetration of the problem"; "Bach was unique in his handling of counterpoint"; "craftsmen whose skill is unequaled"; "unparalleled athletic ability"; "a breakdown of law unparalleled in our history" [syn: alone(p), unequaled, unequalled, unparalleled]
2 (followed by `to') applying exclusively to a given category or condition or locality; "a species unique to Australia" [syn: unique(p)]
3 the single one of its kind; "a singular example"; "the unique existing example of Donne's handwriting"; "a unique copy of an ancient manuscript"; "certain types of problems have unique solutions" [syn: singular]
4 highly unusual or rare but not the single instance; "spoke with a unique accent"; "had unique ability in raising funds"; "a frankness unique in literature"; "a unique dining experience"
- Rhymes: -iːk
Adjectiveunique (comparable only in disputed usage)
- Unique in its undisputed sense is not comparable. In its disputed senses, however, it can be compared as more unique, most unique, and occasionally as uniquer, uniquest.
one of a kind
- Arabic: ,
- Czech: jedinečný
- Dutch: uniek
- Esperanto: unika
- French: unique
- German: einzigartig
- Greek: μοναδικός (monadikós)
- Korean: 독특하다
- Portuguese: único
- Russian: уникальный, исключительный, единственный
- Spanish: único, única
In mathematics and logic, the phrase "there is one and only one" is used to indicate that exactly one object with a certain property exists. In mathematical logic, this sort of quantification is known as uniqueness quantification or unique existential quantification.
Uniqueness quantification is denoted with the symbol "∃!". For example, the formal statement
- \exists! n \in \mathbb\,(n - 2 = 4)
Reduction to ordinary existential and universal quantification
Uniqueness quantification can be expressed in terms of the existential and universal quantifiers of predicate logic by defining the formula ∃!x P(x) to mean
- \exists x\,(P(x) \And \forall y\,(P(y) \to x = y)).
- \exists x\,P(x) \And \forall y\, \forall z\,(P(y) \And P(z) \to y = z).
- \exists x\,\forall y\,(x = y \leftrightarrow P(x)).
One generalization of uniqueness quantification is counting quantification. This includes both quantification of the form "exactly k objects exist such that ..." as well as "infinitely many objects exist such that ..." and "only finitely many object exist such that...". The first of these forms is expressible using ordinary quantifiers, but the latter two cannot be expressed in ordinary first-order logic.
unique in French: Unicité (mathématiques)
unique in Dutch: Uniciteit
unique in Swedish: Unik
unique in Turkish: Biricik
unique in Chinese: 唯一量化
a certain, absolute, almost unheard-of, alone, an, another, any, any one, appropriate, atomic, authentic, avant-garde, azygous, beguiling, bewildering, beyond compare, beyond comparison, breakaway, celibate, characteristic, creative, different, distinctive, distinguished, easily first, either, else, enigmatic, exceptional, exclusive, extraordinary, fabulous, facile princeps, fantastic, fascinating, first and last, firsthand, fresh, idiocratic, idiosyncratic, imaginative, immortal, impair, in character, incomparable, incomprehensible, inconceivable, incredible, individual, indivisible, infrequent, inimitable, integral, intrinsic, invincible, irreducible, lone, marked, marvelous, matchless, miraculous, monadic, monistic, new, not that sort, not the same, not the type, novel, nulli secundus, odd, of a sort, of another sort, of sorts, offbeat, one, one and only, only, only-begotten, original, other, other than, otherwise, outlandish, particular, passing strange, peculiar, peerless, phenomenal, prodigious, proper, puzzling, quintessential, rare, recherche, remarkable, revolutionary, scarce, second to none, seldom met with, seldom seen, sensational, separate, simple, single, singular, slow, sole, solid, solitary, solo, sparse, special, strange, striking, stupendous, sui generis, true to form, unanalyzable, unapproachable, unapproached, unbeatable, uncommon, uncustomary, underived, undivided, undreamed-of, unequaled, unexampled, unexcelled, unexpected, unfamiliar, unfrequent, unheard-of, uniform, unimaginable, unitary, unmatchable, unmatched, unordinary, unpaired, unparagoned, unparalleled, unpeered, unprecedented, unrepeatable, unrepeated, unrivaled, unsurpassable, unsurpassed, unthinkable, unthought-of, unusual, unwonted, whole, without equal, without parallel, wonderful, wondrous