A synonym for tired or exhausted. It might be accompanied by an overwhelming urge to do nothing more than chill out at home on the sofa / couch and do nothing,
I'm really looking forward to getting home. I feel really flumpy, I just want to chill out.
I'm really flumpy today, and I don't feel like doing much at all
I'm so flumpy, I don't feel ready to get out of bed!