ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: translation of Medieval Latin cantus planus
1. : the ancient nonmetrical monophonic chant of the church service that is based on the ecclesiastical modes and is used today in some liturgical churches — called also plainchant ; compare ambrosian chant , cantus firmus 1, gregorian chant
2.
a. : a chant melody used as a cantus firmus for contrapuntal treatment
b. : cantus firmus 2 — compare prick song
3. : a simple air or melody