n. 无以匹敌的人, 无与伦比的事物

[ noun ]
model of excellence or perfection of a kind; one having no equal
<noun.person>

Nonesuch \None"such`\, n.
A person or thing of a sort that there is no other such;
something extraordinary; a thing that has not its equal. It
is given as a name to various objects, as to a choice variety
of apple, a species of medic ({Medicago lupulina}), a variety
of pottery clay, etc.