Singular of accidense, an accident being one thing and accidense being a bunch, often noticeable as a swarm.
An accident is nature's way of demonstrating that you still have things to learn.
It is an occurrence, an incident, an event, and sometimes a good excuse for a party, but not often. Mostly it's something that happens or something that just falls out, like maybe an anvil falling out of a window and landing on your shadow (a good excuse for a party), or your head (not!).
Fortunately, on hiking trails, anvils are rare and second story windows even rarer. So on the trail your accident (if you are lucky enough to have one) is more likely to be setting your pants on fire, or having someone do it for you. Accidentally.
Which means you can't legally kill them. Neener, neener, neener.