Definition of unique

• 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"
• (followed by `to) applying exclusively to a given category or condition or locality; "a species unique to Australia"
• the single one of its kind; "a singular example"; "the unique existing example of Donnes handwriting"; "a unique copy of an ancient manuscript"; "certain types of problems have unique solutions"