modal

(noun) an auxiliary verb (such as `can' or `will') that is used to express modality. Synonyms: modal auxiliary verb, modal auxiliary, modal verb.

(adj) relating to or constituting the most frequent value in a distribution. Synonyms: modal(prenominal), average. Example: "The modal age at which american novelists reach their peak is 30."

(adj) of or relating to a musical mode; especially written in an ecclesiastical mode.

(adj) relating to or expressing the mood of a verb. Example: "Modal auxiliary."