Any of various engines in which compression and expansion of the working fluid occurs in a space created by a nutating or rotating disc in an enclosed chamber; (in later use) specifically an internal-combustion engine involving a nutating disc.
The earliest engines of this type were steam engines (an early one, with a nutating disc, was invented by Edward and James Dakeyne in 1830)..
Origin
Mid 19th century; earliest use found in The Mechanics' Magazine.