What is "indeterminably"

Indeterminable \In`de*ter"mi*na*ble\, a. [L. indeterminabilis: cf. F. ind['e]terminable. See In- not, and Determine.] Not determinable; impossible to be determined; not to be definitely known, ascertained, defined, or limited. -- In`de*ter"mi*na*bly, adv.

adv. in an indeterminable manner

adv. in an indeterminable manner; "their relationship was of an indeterminably vague nature"