unbend

straighten up or out; make straight

unfasten, as a sail, from a spar or a stay

free from flexure; "unbend a bow"

make less taut; "relax the tension on the rope"

become less tense, rest, or take one's ease; "He relaxed in the hot tub"; "Let's all relax after a hard day's work"

release from mental strain, tension, or formality; "unbend the mind from absorbing too much information"