Auxiliary (adjective)
Helping; giving assistance or support.
“auxiliary troops”
“ancillary|accessory”
Auxiliary (adjective)
Supplementary or subsidiary.
Auxiliary (adjective)
Held in reserve for exceptional circumstances.
Auxiliary (adjective)
Of a ship, having both sails and an engine.
Auxiliary (adjective)
Relating to an auxiliary verb.
Auxiliary (noun)
A person or group that acts in an auxiliary manner.
Auxiliary (noun)
A sailing vessel equipped with an engine.
Auxiliary (noun)
An auxiliary verb.
Auxiliary (noun)
A marching band colorguard.
Ancillary (adjective)
Subordinate; secondary; auxiliary
“accessory”
Ancillary (noun)
Something that serves an ancillary function, such as an easel for a painter.
Ancillary (noun)
An auxiliary.
Wiktionary