To remove a bend so as to make, or allow to become, straight
to unbend a bow
To release (a load) from a strain or from exertion; to set at ease for a time; to relax.
to unbend the mind from study or care
To unfasten sails from the spars or stays to which are attached for use.
To cast loose or untie
Unbend the rope.
To cease to be bent; to become straight.
To relax in exertion, attention, severity, or the like
To enjoy oneself; to become affable and free from formality