``disown`` removes the specified :ref:`job <syntax-job-control>` from the list of jobs. The job itself continues to exist, but fish does not keep track of it any longer.
Jobs in the list of jobs are sent a hang-up signal when fish terminates, which usually causes the job to terminate; ``disown`` allows these processes to continue regardless.
If no process is specified, the most recently-used job is removed (like :ref:`bg <cmd-bg>` and :ref:`fg <cmd-fg>`). If one or more PIDs are specified, jobs with the specified process IDs are removed from the job list. Invalid jobs are ignored and a warning is printed.
If a job is stopped, it is sent a signal to continue running, and a warning is printed. It is not possible to use the :ref:`bg <cmd-bg>` builtin to continue a job once it has been disowned.
``firefox &; disown`` will start the Firefox web browser in the background and remove it from the job list, meaning it will not be closed when the fish process is closed.