Miller's exhaustive (possibly exhausting) dictionary defines this to be...
pre, during, or even post Christmas energetic outburst of any type, form, (or for that matter time of the year)
symptoms (not limited to) but may include crying, irrationality, frustration, possibly throwing of objects...or just in general the need for a personal "time-out"
This behavior has been found to be not entirely out of the norm to the human race. In fact, Jesus came to save us from, give us a change of heart/mind during, and fill us with hope to face the moments after. Hallelujah. What a Savior!