Similar to Halo, where you first get any type of multi-kill, ie: double, tripple... then on to overkill. To achieve this you must be doing more than two tasks of any sort because less that three is but mere multitasking.
Mac: Bro, the other night I was downing a beer and texting at the same time, then my buddy gives me a high-five right in the middle of all this cause some fine b*tches walked in.
Jesse: Damn son, you were over-tasking like a pro.
Mac: Straight up.