In a singular manner; in a manner, or to a degree, not common to others; extraordinarily; as, to be singularly exact in one's statements; singularly considerate of others.

in a singular manner or to a singular degree; "Lord T. was considered singularly licentious even for the courts of Russia and Portugal; he acquired three wives and fourteen children during his Portuguese embassy alone"

Strangely; oddly; as, to behave singularly.

So as to express one, or the singular number.