underhungover (adj.) being in the condition, after a somewhat steamy night out, of feeling suspiciously unpained and clear-headed the following morning; usually symptomatic of being still inebriated. Differs from gintrospection (q.v.) in that it occurs at one’s usual rising time, and is accompanied by a sense of well-being and relief.
Fortunately, being nowhere near as debauched as the pose I like to strike in my online persona, underhangovers are a rare occurrence for me.