Unparalleled, a.
Having no parallel, or equal; unequaled; unmatched. The unparalleled perseverance of the armies of the United States, under every suffering and discouragement, was little short of a miracle. Washington.
Shades of meaning
Fernald has no entry of its own for unparalleled; he lists it under rare.
He lists it without comment; the entries above explain its neighbors.