adjective
No longer in use or active, nor expected to be again.
(computing) Specifically, of a process: having terminated but not having been reaped (by its parent or an inheritor), and thus still occupying a process slot. See also zombie, zombie process.
(linguistics) (of a language) No longer spoken.
(now rare) Deceased, dead.
verb
To make defunct.
noun
The dead person (referred to).