to break faith: to betray a trust one is bound to keep, acting treacherously against the party owed loyalty
This verb is the language of betrayal. It does not name an ordinary sin or mistake; it names the breaking of a bond that one was obligated to honor, so the wrong is felt as treachery by the party who trusted. In the Bible that party is almost always God, and the act is breaking covenant with him: turning to other gods, defying his word, defiling his sanctuary, or holding back what is his.
The word travels in a tight circle of settings. It is the priestly term for sacrilege, the wrong of laying hands on what has been set apart as holy or devoted to God, as when Achan took plunder under a ban. It is the prophets' and the Chronicler's verdict on a nation that abandoned the LORD, the charge that explains why the land was laid waste and the people carried off. And in one striking case it describes a wife who is unfaithful to her husband, treating the most intimate human bond the way Israel treated its bond with God.
Underneath every use is the same idea: a relationship carried a real claim, and that claim was violated by the one bound to it. English splits this across several words, and the matching noun from the same root often stands right beside it, so the phrase reads literally as breaking faith with a breach of faith. The senses below are shades of one act, not separate words.