Unique

Part of speech: noun (n.)

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

Part of speech: adjective (a.)

Being without a like or equal; unmatched; unequaled; unparalleled; single in kind or excellence; sole. -- U*nique"ly, adv. -- U*nique"ness, n.