Performing on a comedy show with an audience full of only other comedians and no civilians.*
An undesirable circumstance, when a comedian's external environment is as empty as their internal one.**
* The term "civilians" refers to members of the general public, those not enlisted in the army of comedy.
This army's weaponry includes seltzer spray-bottles, pies in the face, and fart jokes.
Also fart machines, fart noises, and farts.
** This is not at all to suggest that every comedian is empty inside.
Of course, many are quite full.
(Of depravity, ignorance, and leftover face-pie.)