alone, unique, unequaled, unequalled, unparalleled -- (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")
unique -- ((followed by `to') applying exclusively to a given category or condition or locality; "a species unique to Australia")
singular, unique -- (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")
unique -- (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")
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