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

3. (Gram.)

Defn: 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.

4. (Math.)

Defn: A quantity introduced for the purpose of simplifying or facilitating some operation, as in equations or trigonometrical formulæ. Math. Dict.

AUXILIATORY
Aux*il"ia*to*ry, a.

Defn: Auxiliary; helping. [Obs.]

AUXOMETER
Aux*om"e*ter, n. [Gr. to increase + -meter.] (Optics)

Defn: An instrument for measuring the magnifying power of a lens or system of lenses.

AVA
A"va, n.