(1) Opposite of abiotic.
(2) Animals behaving badly.
From "bio", meaning a living thing, and "idiotic", meaning doing really dumb stuff.
Drunken elephants come to mind.
Cockroaches on drugs.
(3) Living material, or where the living material lives.
If you are a backpacker, this may (sadly) be living stuff inside your clothing, or even in your underwear if you haven't washed lately.
By biotic we don't mean you when we say living material, but something else that is there but shouldn't be.
Backpacking aside, living material is in the biotic zone. That is, you find living things where living things can sit down for a break, maybe have a smoke, and not die, like from lack of oxygen.
If you want to die from lack of oxygen you have to go to the abiotic zone.
It's pretty quiet there. A good place for a long, long nap.