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. [1913 Webster] {Auxiliary scales} (Mus.), the scales of relative or attendant keys. See under {Attendant}, a. {Auxiliary verbs} (Gram.). See {Auxiliary}, n., 3. [1913 Webster]