'Plagal' definitions:
Definition of 'Plagal'
From: GCIDE
- Plagal \Pla"gal\ (pl[=a]"gal), a. [F., from Gr. pla`gios sidewise, slanting.] (Mus.) Having a scale running from the dominant to its octave; -- said of certain old church modes or tunes, as opposed to those called authentic, which ran from the tonic to its octave. [1913 Webster]
- Plagal cadence, a cadence in which the final chord on the tonic is preceded by the chord on the subdominant. [1913 Webster]