Definitions
1.nounA form of monophonic chant in unison using the Gregorian scale, sung in various Christian churches.
2.nounA cantus firmus or theme chosen for contrapuntal treatment; so called because often an actual fragment of plain-song.
3.nounThe simple notes of an air, without ornament or variation.
4.noun(by extension) A plain unvarnished statement, without exaggeration.