ass-hisstance

Refers to one or more whooshy/odiferous anal-exhalations dat someone "helpfully" releases on your behalf, such as to provide auditory and/or olfactory "cover" for a fart or other raucous/stinky social indiscretion of your own, to join with others in providing a fartification-line for keeping a less-than-welcome/desirable human at bay, etc.

I can't help snickering in certain public situations where something extremely laugh-inducing occurs but expressing amusement would e considered rude, so I always bring along a baked-beans-loving buddy to provide emergency ass-hisstance in such instances.