1. The process used to simplify a useful system or process that was once simple, but because of its use over time has become complex, unwieldy, or unusable.
2. The process used to make something easier out of something worthwhile that is not easy to use.
Origin: Don Morgan created this humorous, oxymoron-like, but useful word around 1994 while serving in the U.S. Army.
The introduction of the 1040EZ form by the U.S. Internal Revenue Services was a result of the decomplexification of the original 1040 tax form.