æquison

• equison (standard spelling)

Borrowed from Latin aequisonus, from aequus (“equal”) in combination with sonus (“sounding”).

• (Received Pronunciation) enPR: ĕʹkwĭsən, IPA^(key): /ˈɛkwɪsən/

æquison (plural æquisons)

1. (rare, music) Archaic spelling of equison.
   • 1609, John Dowlan, Andreas Ornithoparcus: His Micrologus, or Introduction: Containing the Art of Singing, page 79:

     Æquisons are those notes, which being stroke together, make one sound of 2.

• “†ˈequison¹” listed in the Oxford English Dictionary [2^nd Ed.; 1989]

• sequoian