A period during summer in which a person performs inefficiently due to the excessive amount of free time on their hands.
The symptoms often include:
-remaining around the house for the majority of the day,
-sleeping in excessive amounts,
-persistent viewing of television,
-prolonged exposure to video games,
-neglecting personal hygiene,
-consuming large quantities of food (in most cases, junk food),
-loss of desire to leave their residence,
-and abstaining contact from the outside world other than Myspace/Facebook or the occasional trip to 7-11.
Causes: Lack of school or a job, absence of friends, insufficient funds, and/or lack of transportation.
Effects: Moodiness, weight gain, shortness of breath (most likely when a patient returns to school and must run the mile), insomnia, increase of nerdiness, shrinkage of intimacy, and/or depression.
Two weeks into summer vacation, Tom fell into the Summer Slump and we didn't see him for two months.
When we returned to school he mentioned that he had become a tenth prestige on "CoDWaW." We noticed that he had gained a few pounds and had broken up with his girlfriend, clearly effects of the Summer Slump.