renouncement, renunciation - an act (spoken or written) declaring that something is surrendered or disowned

giving up, yielding, surrender - a verbal act of admitting defeat

ending, termination, conclusion - the act of ending something; "the termination of the agreement"

ceding, cession - the act of ceding

handover - act of relinquishing property or authority etc; "the handover of occupied territory"

waiver, discharge, release - a formal written statement of relinquishment