unique (Adjective) — Radically distinctive and without equal. ex. "Bach was unique in his handling of counterpoint"
unique (Adjective) — (followed by 'to') applying exclusively to a given category, condition or locality. ex. "a species unique to Australia"
unique (Adjective) — The single one of its kind. ex. "the unique existing example of Donne's handwriting" ex. "a unique copy of an ancient manuscript" ex. "certain types of problems have unique solutions"
unique (Adjective) — Highly unusual or rare but not the single instance. ex. "spoke with a unique accent" ex. "had unique ability in raising funds" ex. "a frankness unique in literature" ex. "a unique dining experience"