The phrase "restrained oneself" refers to controlling or restricting one's actions or emotions. There are a variety of synonyms for this phrase, including "exercised self-control," "held back," "kept in check," "curbed," "moderated," and "reigned in." Other words or phrases that convey a similar meaning include "temperance," "restraint," "discipline," "self-restraint," "moderation," and "self-discipline." These synonyms are particularly useful when describing situations in which someone exhibited restraint, such as resisting the urge to speak out of turn, keeping emotions in check, or refraining from indulging in excessive behavior. Overall, these synonyms imply a level of maturity, control, and self-awareness.