Besmirch oneself implies doing something that brings disgrace or shame to oneself. Some synonyms for besmirch oneself can be self-disparage, self-deprecate, self-inflict, self-ruin, or self-taint. These words suggest taking actions that damage one's reputation or honor. Additionally, one may use the phrase "sully oneself," meaning they have debased themselves or tarnished their character. Another alternative is "defile oneself," which implies that someone has corrupted their purity or innocence. In conclusion, besmirching oneself is an unpleasant and unwise choice, and using these synonyms, we can better articulate the seriousness of this action.