1. (adj)aide, auxiliary someone who acts as assistant
2. (adj)auxiliary, subsidiary, supplemental, supplementary functioning in a supportingcapacity "the main library and its auxiliary branches"
3. (adj)accessory, adjunct, ancillary, adjuvant, appurtenant, auxiliary furnishing added support "an ancillary pump"; "an adjuvant discipline to forms of mysticism"; "The mind and emotions are auxiliary to each other"
Definitions of 'auxiliary'
Webster 1913 Dictionary
1. (adj)auxiliary conferring aid or help; helping; aiding; assisting; subsidiary; as auxiliarytroops
3. (noun)auxiliary foreign troops in the service of a nation at war; (rarely in sing.), a member of the allied or subsidiary force
4. auxiliary 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
5. auxiliary a quantity introduced for the purpose of simplifying or facilitating some operation, as in equations or trigonometrical formulae
Definition of auxiliary 
