Definify.com

Webster 1913 Edition

adv.

In the way of conclusion; decisively; positively.

Burke.

adv.

Decisively; with final determination; as, the point of law is conclusively settled.

conclusively ‎(comparative more conclusively, superlative most conclusively)

In a conclusive manner; with finality.
Once the final experiment had been performed, the theory was conclusively proved.

in a conclusive manner