/sī-kəl əv rē-in-kär-ˈnā-shən/
[coined by Ivan Sutherland ca. 1970]
n. Term used to refer to a well-known effect whereby function in a computing system family is migrated out to special-purpose peripheral hardware for speed, then the peripheral evolves toward more computing power as it does its job, then somebody notices that it is inefficient to support two asymmetrical processors in the architecture and folds the function back into the main CPU, at which point the cycle begins again.