Asservating is a term commonly used in legal or formal writing which means to assert or declare something in a forceful or emphatic manner. Some synonyms for asservating include affirming, averring, avowing, declaring, maintaining, proclaiming, professing, and swearing. These words all convey a strong degree of certainty or conviction in the statement being made. Other synonyms include attesting, confirming, testifying, and vouching, which imply that the statement being made is supported by evidence or witnesses. In any case, the use of synonyms for asservating can help to add variety and emphasis to your writing, particularly when making a bold or important claim.