auxiliary

From Latin auxiliārius (“assistant, ally”), equiv. to auxiliāris (“helping, aiding”), from auxilium (“help, aid”), from augēre (“to increase”).

• (Received Pronunciation) IPA^(key): /ɔːɡˈzɪl(j)əɹi/, /ɔːɡˈzɪli.əɹi/

• Audio (Southern England)

  (file)

• (General American) IPA^(key): /ɔɡˈzɪl(j)(ə)ɹi/, /ɔɡˈzɪliɛɹi/
  • (cot–caught merger) IPA^(key): /ɑɡˈzɪl(j)(ə)ɹi/, /ɑɡˈzɪliɛɹi/
• Rhymes: -ɪliəɹi
• Rhymes: -ɪliɛəɹi
• Rhymes: -ɪləɹi

auxiliary (not comparable)

1. Helping; giving assistance or support.

   auxiliary troops

   Synonyms: ancillary, accessory

2. Supplementary or subsidiary.
3. Held in reserve for exceptional circumstances.
4. (nautical) Of a ship, having both sails and an engine.
5. (grammar) Relating to an auxiliary verb.

• (supplementary): accessory
• (having sails and engine): motorsailer

auxiliary (plural auxiliaries)

1. A person or group that acts in an auxiliary manner.
   • 1950 November, “Mixed-Traffic Diesel-Electric Locomotives for Ireland”, in Railway Magazine, page 781:

     Auxiliaries and ancillaries are comprehensive, and include a Westinghouse motor-driven recriprocating compressor used for locomotive braking and general service air, two rotary exhauster sets for train brakes when hauling passenger or fitted freight trains, and an oil-fired train heating boiler.

   • 1962 September, G. Freeman Allen, “The New Look in Scotland's Northern Division—1”, in Modern Railways, page 163:

     A drive to exploit the Highlands as a winter sports area, with all the necessary auxiliaries, such as chair lifts in the Cairngorms, shows increasing promise, [...].

2. A sailing vessel equipped with an engine.
3. (grammar) An auxiliary verb.
   • 1988, Andrew Radford, Transformational grammar: a first course, Cambridge, UK: Cambridge University Press, page 151:

     The three traditionally recognized Non-modal Auxiliaries are the per-
     fective Auxiliary have, the progressive Auxiliary be, and the passive Auxiliary
     be. Perfective have is so-called because it marks the completion (hence, perfec-
     tion) of an action; it is followed by a VP headed by a perfective -n participle, as
     in:
     (121)    The referee has [_VP shown him the red card]

4. A marching band colorguard.

• axillary

• “auxiliary”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “auxiliary”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.
• “auxiliary”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.