noun
1. a construction that can be used to extend the meaning of a word or phrase but is not one of the main constituents of a sentence
2. something added to another thing but not an essential part of it
3. a person who is an assistant or subordinate to another
adj
1. of or relating to a person who is subordinate to another
Synonym: assistant
2. furnishing added support
e.g. an ancillary pump
an adjuvant discipline to forms of mysticism
The mind and emotions are auxiliary to each other
Synonym: accessoryancillaryadjuvantappurtenantauxiliary