Definify.com

Webster 1913 Edition

Adj.

Free from fear or suspicion.

[Obs.]

Pretty child, sleep

doubtless

and secure.

Shakespeare

adv.

Undoubtedly; without doubt.

Adj.

Free from fear of danger; secure.

Pretty child, sleep doubtless and secure.

adv.

Without doubt or question; unquestionably.

The histories of Christ by the evangelists are doubtless authentic.