super-octave
/ˌsuːpərˈɒktɪv/ /ˌsjuːpərˈɒktɪv/ /ˌsuːpərˈɒkteɪv/Music
noun
1An organ stop sounding a note two octaves higher than the ordinary pitch; the octave two octaves above a given note.
2In full superoctave coupler. A device in an organ or similar instrument which enables a note one octave higher than that being played to sound at the same time.
Origin
Late 18th century; earliest use found in John Hawkins (1719–1789), music scholar and lawyer. From super- + octave.