modal

Concise Oxford English Dictionary © 2008 Oxford University Press:
modal /ˈməʊd(ə)l/

▶adjective

• 1 relating to mode or form as opposed to substance.

• 2 Grammar of or denoting the mood of a verb.

  ■ relating to a modal verb.

• 3 Statistics occurring most frequently in a population.

• 4 (of music) using melodies or harmonies based on modes other than the ordinary major and minor scales.

• 5 Logic (of a proposition) in which the predicate is affirmed of the subject with some qualification or condition.

– derivatives
modally adverb.