2. To deny something to oneself; to restrain; especially, from indulging in some pleasure: The minister of the church abnegated the material luxuries of life.
When Agnes Marcia became a nun after the deaths of her son and husband in an auto accident, she was abnegating a life of comfort and ease in order to dedicate her life to God.
Indulging in an ice cream sundae abnegates the healthful effects of having a salad for lunch.
Because Lucy wants to lose weight, she is abnegating eating so much food during her meals.