unique

In mathematics, unambiguous and singly determinate.

Only; single.

Having no like or equal; unmatched; sole; unequaled; single in its kind or excellence: often used relatively, and then signifying rare, unusual.

A unique thing; a thing unparalleled or sole of its kind.

A thing without a like; something unequaled or unparalleled.

Being without a like or equal; unmatched; unequaled; unparalleled; single in kind or excellence; sole.

Being the only one of its kind; unequaled, unparalleled or unmatched.

Of a feature, such that only one holder has it.

Of a rare quality.

Unusual.