c.1600, from Latin auxiliaris "helpful," from auxilium "aid, help, support," related to auctus, past participle of augere "to increase" (see augment).
"foreign troops in service of a nation at war," c.1600, from auxiliary (adj.). Related: Auxiliaries.
auxiliary aux·il·ia·ry (ôg-zĭl'yə-rē, -zĭl'ə-rē)adj.
Functioning in an augmenting capacity; supplementary.
Functioning as a subordinate; secondary.