When it comes to synonyms for "broke one promise," there are many words that could accurately describe the situation. Some potential options include words like "reneged," "backtracked," "failed," "betrayed," "violated," and "dishonored." Each of these words carries a slightly different connotation, but they all share the sense of someone breaking an agreement or not following through on their word. Whether someone has reneged on a promise to pay back a loan, failed to keep their word about a job opportunity, or violated a previously-agreed-upon rule, these synonyms all capture the sense of disappointment and frustration that can arise when promises are broken.