Describes sosmeone who suddenly turns extremely and uncharacteristically grumpy at night, particularly after midnight. Word evolved from pumpkin - someone who suddenely turns sleepy at midnight.
by Grumpkin April 16, 2006
Used to describe someone who suddenely becomes extremely tired, incoherent, and who may fall into a deep sleep at night - especially if if the transformation occurs at midnight. Often used in as an affectionate descriptor and a form of endearment.
by Grumpkin April 16, 2006