MEANING: adjective:
1. High-energy; powerful; dynamic.
2. In relation to engine fuels, having a high octane number resulting in anti-knock properties and higher efficiency.

ETYMOLOGY: Octane number is a measure of anti-knock properties of a fuel used in engines. A high octane number indicates greater resistance to engine knocking. The term octane refers to hydrocarbons with eight carbon atoms. Earliest documented use: 1931.

HIGH OCTAVE - the rightmost thirteen keys on a piano

HIGH OCTANT - when you throw your navigation aid way up in the air

HIGH OCTASE - a condition characterized by too much of the enzyme Octase