auxiliary

American  

[awg-zil-yuh-ree, -zil-uh-] / ɔgˈzɪl yə ri, -ˈzɪl ə- /

adjective

1. additional; supplementary; reserve.

   an auxiliary police force.

2. used as a substitute or reserve in case of need.

   The hospital has an auxiliary power system in case of a blackout.

   Synonyms:

   secondary, ancillary, backup

3. (of a boat) having an engine that can be used to supplement the sails.

   an auxiliary yawl.

4. giving support; serving as an aid; helpful.

   The mind and emotions are auxiliary to each other. Passion is auxiliary to art.

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noun

auxiliaries plural

1. a person or thing that gives aid of any kind; helper.

   Synonyms:

   help, assistant, ally, aide

2. an organization allied with, but subsidiary to, a main body of restricted membership, especially one composed of members' relatives.

   The men's club and the ladies' auxiliary were merged into one organization.

3. auxiliary verb.

4. auxiliaries, foreign troops in the service of a nation at war.

5. Navy. a naval vessel designed for other than combat purposes, as a tug, supply ship, or transport.

6. Nautical. a sailing vessel carrying an auxiliary propulsion engine or engines.

auxiliary British  

/ -ˈzɪlə-, ɔːɡˈzɪljərɪ /

adjective

1. secondary or supplementary

2. supporting

3. nautical (of a sailing vessel) having an engine

   an auxiliary sloop

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noun

1. a person or thing that supports or supplements; subordinate or assistant

2. nautical

   1. a sailing vessel with an engine

   2. the engine of such a vessel

3. navy a vessel such as a tug, hospital ship, etc, not used for combat

Other Word Forms

Inflected Forms

noun

• auxiliaries
  plural

Etymology

Origin of auxiliary

1595–1605; < 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 suffix) + -ārius -ary

Explanation

When you're offering something in support of an already existing thing, you're offering something auxiliary. The auxiliary police will help out the regular police with things like directing traffic and crowd control when there's a special event in town. The Latin word auxilium means "help," and so auxiliary means something that "helps" by providing backup or support. Think of auxiliary verbs (sometimes called helper verbs), that provide support within a verb phrase, as "is" does in "Helen is playing." You can have an auxiliary engine in a car, an auxiliary cook at a restaurant, an auxiliary electrical network at a factory, or auxiliary troops standing by during battle. A "Ladies Auxiliary" functions as support for institutions such as churches, synagogues, or charities.

Example Sentences

The Veterans of Foreign Wars post in Webster Springs, W.VA., was planning vigils for Thursday, Friday and Saturday at the memorial wall in the town, according to the Webster County Veterans Auxiliary.

From The Wall Street Journal • Nov. 27, 2025

He had not lost his love of flying and he signed up with the Royal Auxiliary Air Force as a part-time pilot.

From BBC • Jul. 8, 2025

Auxiliary Bishop Evelio Menjivar: “Do you not see the suffering? Is your conscience not disturbed? How can you stay quiet?”

From Los Angeles Times • May 8, 2025

The girls’ program was funded by a separate organization, the American Legion Auxiliary, had a dress code that some deemed too strict and didn’t schedule sports activities the way the boys’ did.

From Seattle Times • Apr. 3, 2024

By the middle of 1942, the Air Transport Auxiliary in the United Kingdom let women ferry every single type of aircraft that the men of the Royal Air Force flew.

From "A Thousand Sisters" by Elizabeth Wein

Related Words

• ancillary