adjective

1. of or indicating a mode or mood
2. Gram. of or expressing mood a modal auxiliary
3. 1. Jazz of or relating to compositions or improvisations based on an arrangement of modes rather than a series of chord progressions
   2. in popular music, of or characterized by the repetition of one or two chords as a harmonic base
4. Logic expressing or characterized by modality
5. Music of or composed in any of the medieval church modes
6. Philos. of mode, or form, as opposed to substance
7. Statistics having to do with a statistical mode

Etymology: ML modalis < L modus, mode

noun