Glossary
What is a high performance airplane?
An airplane with an engine above the horsepower threshold written into the federal regulations. Like a complex airplane it needs its own one-time instructor endorsement, and the two categories are independent: an airplane can be one, the other, both or neither.
That is the whole entry for now. The longer version, with the mechanics and worked examples, is still to be written. See autorotation for how those read once they exist.