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

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

Foreign troops in the service of a nation at war;
(rarely in sing.), a member of the allied or subsidiary force.

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; etre and avoir, in
French; avere and essere, in Italian; estar and haber, in Spanish.