'modal auxiliary' definitions:
Definition of 'modal auxiliary'
From: WordNet
noun
An auxiliary verb (such as `can' or `will') that is used to express modality [syn: modal auxiliary verb, modal auxiliary, modal verb, modal]
Definition of 'modal auxiliary'
From: GCIDE
- modal auxiliary \mo"dal aux*il"iar*y\(Gram.), n. Any one of the auxiliary verbs of English, such as can, may, will, shall, must, might, could, would, or should, which are used together with the infinitive form of another verb to express distinctions of mood[2], such as uncertainty, possibility, command, emphasis, and obligation. [PJC]