warrant

1. noun /ˈwɒɹənt/

a) Authorization or certification; sanction, as given by a superior.

Than for pité I made the damesell to lepe on her palferey, and I promysed her to be her waraunte and to helpe to entyre her lorde.<!

b) Something that provides assurance or confirmation; a guarantee or proof: a warrant of authenticity; a warrant for success.

Ill warrant him for drowning; though the ship were no stronger than a nutshell and as leaky as an unstanched wench.

2. verb /ˈwɒɹənt/

a) To guarantee (something) to be (of a specified quality, value etc.).

all honest meanes for a man to warrant himselfe from evils are not onely tolerable, but commendable.

b) To guarantee as being true; to believe strongly.

His pure tight skin was an excellent fit; and closely wrapped up in it, and embalmed with inner health and strength, like a revivified Egyptian, this Starbuck seemed prepared to endure for long ages to come, and to endure always, as now; for be it Polar snow or torrid sun, like a patent chronometer, his interior vitality was warranted to do well in all climates.