Formal:
* The king was forced to renounce his claim to the throne.
* She renounced her citizenship of her birth country to become a citizen of her adopted home.
* The religious leader renounced violence and preached peace.
Informal:
* After years of smoking, he decided to renounce cigarettes for good.
* She renounced her old lifestyle and embraced a healthier one.
* He renounced his belief in ghosts after a terrifying encounter.
Literary:
* The young poet renounced the frivolous world of high society to pursue her true passion.
* He renounced his worldly possessions and embarked on a journey of spiritual enlightenment.
Humorous:
* My friend renounced his love of pizza for a month in an attempt to lose weight.
* I renounce all responsibility for the mess my dog made in the house!