1. In an infallible manner.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• infallibale,
• indellibly,
• infalliable,
• infalibly,
• infalible,
• infallable,
• infallibilty,
• infalliblity,
• unfallibly,
• jnfallibly,
• knfallibly,
• infallobly,
• inffallibly,
• infalliblly,
• infalliblyy,
• Infellibly,
• Infallably,
• inflambly,
• Inflamobly,
• inffalibly

• infallible,
• inapplicable,
• inflexibly,
• infallibility,
• in flight,
• invaluable,
• inability,
• in full.

The adjective form of the word "infallibly" is "infallible".

The plural form of the word "infallibly" is "infallibilities".

The singular form of the word "Infallibly" is "Infallible"