Auxiliary — Defs

01 a. Conferring aid or help; helping; aiding; assisting; subsidiary; as auxiliary troops.

1.
Conferring aid or help; helping; aiding; assisting; subsidiary; as auxiliary troops.

Phrases & compounds

Auxiliary scales — the scales of relative or attendant keys. See under Attendant, a.

Auxiliary verbs — See Auxiliary, n., 3.

02 n. A helper; an assistant; a confederate in some action or enterprise.

pl. Auxiliaries

1.
A helper; an assistant; a confederate in some action or enterprise.
2.
Foreign troops in the service of a nation at war; (rarely in sing.), a member of the allied or subsidiary force.(Mil.)
3.
A verb which helps to form the voices, modes, and tenses of other verbs; -- called, also, an auxiliary verb; as, have, be, may, can, do, must, shall, and will, in English; être and avoir, in French; avere and essere, in Italian; estar and haber, in Spanish.(Gram.) Also: auxiliary verb
4.
A quantity introduced for the purpose of simplifying or facilitating some operation, as in equations or trigonometrical formulæ.(Math.)