Webster's Revised Unabridged Dictionary · 1913

Unique

Unique , adjective

[French unique; compare Italian unico; from Latin unicus, from unus one. See One.]

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

Unique , noun

A thing without a like; something unequaled or unparalleled. [Rare]
The phenix, the unique of birds. — De Quincey