adj. & n.
1. (of a person or thing) that gives help.
2 (of services or equipment) subsidiary, additional.
--n. (pl. -ies)
1. an auxiliary person or thing.
2 (in pl.) Mil. auxiliary troops.
3 Gram. an auxiliary verb.
Phrases and idioms:
auxiliary troops Mil. foreign or allied troops in a belligerent nation's service. auxiliary verb Gram. one used in forming tenses, moods, and voices of other verbs.
Etymology: L auxiliarius f. auxilium help