abjuration (n.)

"solemn renunciation," mid-15c., originally of heresy or idolatry, later of renunciations of oaths generally, from Latin abiurationem (nominative abiuratio) "a denying on oath," noun of action from past participle stem of abiurare "deny on oath," from ab "off, away from" (see ab-) + iurare "to swear," from ius (genitive iuris) "law" (see jurist). Related: Abjuratory. The oath of abjuration is "the negative part of the oath of allegiance" [Century Dictionary].