Definition of plagal in English:

plagal

Pronunciation /ˈplāɡəl/ /ˈpleɪɡəl/

adjective

Music
  • (of a church mode) containing notes between the dominant and the note an octave higher, having the final in the middle.

    • ‘The structure of authentic and plagal Modes was explained, and examples given of melodies formed on them.’

Origin

Late 16th century from medieval Latin plagalis, from plaga ‘plagal mode’, from Latin plagius, from medieval Greek plagios (hēkhos) ‘plagal (mode)’, from Greek plagos ‘side’.