faithfulness
n. B2 Upper Intermediate US //ˈfeɪθfəɫˌnɛs// UK //fˈeɪθfəlnəs// faith·ful·ness
n. the quality of being loyal and honest to someone or something. It means you keep your promises and stay true to your beliefs or a person.
n. the quality of being loyal, honest, or true to a person, belief, or duty. Often describes the accuracy of a representation or the consistency of a relationship.
Her faithfulness to her friends is well-known.
The translator's faithfulness to the original text ensured that the meaning was preserved for the readers.
The long-term success of the marriage was built on a deep-seated faithfulness that neither partner ever questioned, even during the most difficult periods of their lives.
From Middle English feithfulnesse, equivalent to faithful + -ness.