Definify.com

Webster 1913 Edition

adv.

In an infallible manner; certainly; unfailingly; unerringly.

Blair.

adv.

Without a possibility of erring or mistaking.

Certainly; without a possibility of failure. Our Savior has directed us to conduct that will infallibly render us happy.

infallibly ‎(comparative more infallibly, superlative most infallibly)

in an infallible manner