What is the root word of fidelity

Fidēlis is a derivative of the noun fidēs trust, assurance.Faithfulness, devotion, from old french fidélité (15c.), from latin fidelitatem (nominative fidelitas)… see definitions of fidelity.Marital fidelity is faithfulness to your spouse.Fidelity comes from the latin root fides, which means faith, so fidelity is the state of being faithful.It was made up of a latin word and a greek word.It is strict conformity to truth or a fact;

According to the american heritage dictionary of the english language and collins english dictionary, the word fidelity is a noun that means retaining a given quality or being faithful.