Wiktionary
nonreturn
n. Absence of return; failure to come back or bring back.
Usage examples of "nonreturn".
The sour threats to Dominic, the cutting off of fingers, the screams, the nonreturn of the body, all thundered into the office like an echo.
It's one small thread in a vast skein, separated from every other universe by a limitation of constants and qualities, just as death is separated from life by the eternal nonreturn of the dead.
Our nonreturn would damage Zantiu-Braun's interstellar operations permanently, possibly even to the point of shutting them down.
Dammit, why doesn't it have some method of protecting itself against gross physical injury, a nonreturn valve arrangement or some such?