Nonsense technobabble used in a production context.
Reticulating splines started off as an in-joke at Maxis and grew to fame with the widespread popularity of The Sims. While it does have a "real" meaning, this definition isn't actually correct in the context of its use. It's really a programming joke.
Reticulating splines is essentially filler. Don't want to describe what's holding up the program? It's reticulating splines. Why isn't the Internet working? The splines aren't reticulated. Heck, don't want to explain your calculus assignment? We're reticulating splines this week.
See also processor gremlins for the computer hardware equivalent.
Sorry the video took so long to upload. Reticulating splines took hours!
Constructing network based functions that are defined by divisible intervals while approximating said network and composing it of pieces of simple functions defined on subintervals and joined at their endpoints with a suitable degree of smoothness.
Parasites similar to mites that dwell on the head. Or inside...for they have the ability to travel to the brain and subtly take over a human's consciousness.