L5 Lumbar
The L5 Lumbar is the bottom bone of your back and the perfect replacement for the word ASS when you're being extra rude but can't use the real word. It's like your back has a mouth and it's always telling jokes.
My L5 Lumbar is so big it's like it's trying to take over my body.
I used the L5 Lumbar to insult my brother instead of saying the word ASS.
My L5 Lumbar is the reason I can't sit through my favorite show anymore.