The Collaborative International Dictionary
Auxiliary \Aux*il"ia*ry\ (?; 106), a. [L. auxiliarius, fr. auxilium help, aid, fr. augere to increase.] Conferring aid or help; helping; aiding; assisting; subsidiary; as auxiliary troops.
Auxiliary scales (Mus.), the scales of relative or attendant keys. See under Attendant, a.
Auxiliary verbs (Gram.). See Auxiliary, n., 3.
Wiktionary
n. (plural of auxiliary verb English)
Usage examples of "auxiliary verbs".
The only classes of words that were still allowed to inflect irregularly were the pronouns, the relatives, the demonstrative adjectives, and the auxiliary verbs.
The modern Italian has been insensibly formed by the mixture of nations: the awkwardness of the Barbarians in the nice management of declensions and conjugations reduced them to the use of articles and auxiliary verbs.