• WordNet 3.6
    • n tenoroon a tenor bassoon; pitched a fifth higher than the ordinary bassoon
    • ***
Century Dictionary and Cyclopedia
    • n tenoroon Same as oboe da caccia (which see, under oboe).
    • tenoroon In organ-building, noting a stop which does not extend below tenor C: as, a tenoroon hautboy.
    • ***


In literature:

The tenoroon, with which the oboe di caccia has been compared, was a high bassoon really on octave and a fifth below.
"Scientific American Supplement No. 819" by Various