Meaning : Functioning in a supporting capacity.
Example :
The main library and its auxiliary branches.
Synonyms : subsidiary, supplemental, supplementary
Meaning : Furnishing added support.
Example :
An ancillary pump.
An adjuvant discipline to forms of mysticism.
The mind and emotions are auxiliary to each other.
Synonyms : accessory, adjunct, adjuvant, ancillary, appurtenant