Meaning

Hi friends,
In the following text, i couldn't get the meaning of "bone-ass". What's the meaning of it?

“There must be some drug he can take to get rid of this waking dream. No, this waking nightmare: endless tantalization, with no release. Maybe he could ask Charmaine about it: she works in Medical, she could get her hands on something. But how can he explain his needs to her? So crisp, so blue and white, so baby-powder-scented. She wouldn’t understand anything so twisted. Not to mention so plain bone-ass dumb.”

Thanks alot