unbend

/AH0 N B EH1 N D/
verb
  1. 1

    To remove a bend so as to make, or allow to become, straight

    โ€œto unbend a bowโ€

  2. 2

    To release (a load) from a strain or from exertion; to set at ease for a time; to relax.

    โ€œto unbend the mind from study or careโ€

  3. 3

    To unfasten sails from the spars or stays to which are attached for use.

  4. 4

    To cast loose or untie

    โ€œUnbend the rope.โ€

  5. 5

    To cease to be bent; to become straight.

  6. 6

    To relax in exertion, attention, severity, or the like

  7. 7

    To enjoy oneself; to become affable and free from formality

Source: https://en.wiktionary.org/wiki/unbend