modal

Of, relating to, or characteristic of a mode.

Of, relating to, or expressing the mood of a verb.

Of, relating to, characteristic of, or composed in any of the modes typical of medieval church music.

Of or relating to mode without referring to substance.

Expressing or characterized by modality.

Of or relating to a statistical mode or modes.

Pertaining to or affected by a mode; relating to the mode or manner, and not to the substance.

Specifically

Of or pertaining to a grammatical mode.