Sprequal

A follow-up film that takes place both before and after the timeline of the original.

Paranormal Activity 2 is a sprequal because it takes place both before and after the events of the first Paranomal Activity.

Sprequal by Vachon Rahl March 3, 2011

Surequal 

Niether, surplus nor surminus but right in the middle

Most people have an surequal number of ears

When x=x they surequal each other

Surequal by Juan "Surminus" Cena November 20, 2018

Sprequel 

A movie, book, or other form of entertainment that deals with both the future and origin of a series. Basically a prequel and a sequel combined.

The movie Terminator: Salvation is a sprequel because it deals with the future of John Connor and Skynet, but also deals with events before the orginal Terminator, like the creation of the T-800 Model 101 Terminator.

Sprequel by imnotacritic May 28, 2009