Flops
Noun.

The sensation experienced after a very large nicotine headrush. Usually results in slight loss of muscle control, particulary in the neck, and giddy laughter. This intense has the potential to make your head feel grossly overweight, resulting in your head 'flopping' into your chest.
"HAHAHA! OH man I have mad flops right now, I can't feel my face and I can't lift my head!"