L5 Lumbar
The L5 Lumbar is the bottom bone in your back and also the best substitute for the word ASS when you can't say curse words. It's like having a dirty joke in your spine.
My back hurts so much I think my L5 Lumbar is screaming at me.
I told my boss I had a L5 Lumbar problem instead of saying I had an ass problem.
My doctor said my L5 Lumbar is the reason I can't sit still.