Definify.com

Webster 1913 Edition

adv.

In a manner inducing belief;

as, I have been

credibly

informed of the event

adv.

In a manner that deserves belief; with good authority to support belief.

credibly ‎(comparative more credibly, superlative most credibly)

In a credible manner; believably.
Used to report the speaker's assessment of the credibility of a reported statement