eingetreten
Eingetreten is the past participle of the German verb eintreten. Eintreten means to enter or to step into a place, and it can also be used figuratively to mean that something has begun or occurred. The prefix ein- signals direction inward or the onset of a state; treten means to step or to tread.
As a finite verb, eintreten is intransitive and typically uses the auxiliary sein in perfect tenses, because
Eingetreten can also function as an adjective, describing a state that has begun. For example: eine eingetretene
Related terms include betreten (to tread on or enter a place, often transitive) and auftreten (to appear