Толковый словарь английского языка Oxford English Reference - modal

adj. 1 of or relating to mode or form as opposed to substance. 2 Gram. a of or denoting the mood of a verb. b (of an auxiliary verb, e.g. would) used to express the mood of another verb. c (of a particle) denoting manner. 3 Statistics of or relating to a mode; occurring most frequently in a sample or population. 4 Mus. denoting a style of music using a particular mode. 5 Logic (of a proposition) in which the predicate is affirmed of the subject with some qualification, or which involves the affirmation of possiblity, impossibility, necessity, or contingency. Derivatives modally adv. Etymology: med.L modalis f. L (as MODE)