befejezésének
befejezésének is the genitive singular form of the Hungarian word befejezés. Befejezés itself translates to "completion," "finishing," "ending," or "conclusion" in English. Therefore, befejezésének refers to "of its completion," "of its finishing," "of its ending," or "of its conclusion." This grammatical form is used to show possession or a relationship to the act of finishing or completing something.
For example, if one were discussing the completion of a project, the genitive form would be used