Definify.com
Webster 1913 Edition
Infallibly
In-fal′li-bly
,adv.
In an infallible manner; certainly; unfailingly; unerringly.
Blair.
Webster 1828 Edition
Infallibly
INFAL'LIBLY
,adv.
1.
Certainly; without a possibility of failure. Our Savior has directed us to conduct that will infallibly render us happy.