secondary or supplementary supporting
a person or thing that supports or supplements; subordinate or assistant a sailing vessel with an engine the engine of such a vessel
WordReference Random House Learner's Dictionary of American English © 2026
aux•il•ia•ry /ɔgˈzɪlyəri, -ˈzɪlə-/USA pronunciation
adj., n., pl. -ries.
adj.
n. [countable]
WordReference Random House Unabridged Dictionary of American English © 2026adj.
- additional;
secondary;
used as a substitute or reserve when needed: an auxiliary power station. - giving support;
serving as an aid:They served in an auxiliary capacity.
n. [countable]
- a person or thing that gives aid;
helper. - an auxiliary organization:The women's auxiliary raised money for the school.
- Grammar auxiliary verb.
aux•il•ia•ry
(ôg zil′yə rē, -zil′ə-),USA pronunciation adj., n., pl. -ries.
adj.
n.
adj.
- additional;
supplementary;
reserve:an auxiliary police force. - used as a substitute or reserve in case of need:The hospital has an auxiliary power system in case of a blackout.
- Nautical, Naval Terms(of a boat) having an engine that can be used to supplement the sails:an auxiliary yawl.
- giving support;
serving as an aid;
helpful:The mind and emotions are auxiliary to each other. Passion is auxiliary to art.
n.
- a person or thing that gives aid of any kind;
helper. - an organization allied with, but subsidiary to, a main body of restricted membership, esp. one composed of members' relatives:The men's club and the ladies' auxiliary were merged into one organization.
- GrammarSee auxiliary verb.
- Military auxiliaries, foreign troops in the service of a nation at war.
- Military[Navy.]a naval vessel designed for other than combat purposes, as a tug, supply ship, or transport.
- Nauticala sailing vessel carrying an auxiliary propulsion engine or engines.
- Latin auxiliārius assisting, aiding, helping, equivalent. to auxili(um) aid, help (aux(us) increased, augmented (past participle of augēre: aug- increase + -sus, variant of -tus past participle suffix) + -ilium noun, nominal suffix) + -ārius -ary
- 1595–1605
- 2.See corresponding entry in Unabridged backup, ancillary, secondary.
- 5.See corresponding entry in Unabridged aide, ally, assistant; help.
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