Simplexity is a term being used to describe the relationship between simplicity and complexity. Without that label, it’s something I’ve thought about for some time.
A simple interface can hide a complex system. Think of how little I know about how my car works, yet I’m able to drive it without problems. Anything that cuts through the clutter is a simplexity solution. A popular Web example: a search engine ranking the best resources for your input, choosing from millions of pages.
For more “head in the clouds” thoughts on this topic, see how simplicity and complexity are alike.