an·​cil·​lary ˈan(t)-sə-ˌler-ē How to pronounce ancillary (audio)
 especially British  an-ˈsi-lə-rē
: subordinate, subsidiary
the main factory and its ancillary plants
: auxiliary, supplementary
the need for ancillary evidence
ancillary expenses
ancillary equipment
ancillary noun

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Ancillary derives from the English word ancilla, a rare word that means "an aid to achieving or mastering something difficult." That word derives from Latin, in which it means "female servant." While English ancilla is unlikely to be encountered except in very specialized contexts (such as philosophy or quantum computing), ancillary picks up on the notion of providing aid or support in a way that supplements something else. In particular, the word often describes something that is in a position of secondary importance, such as the "ancillary products in a company's line."

Example Sentences

The lockout rocked the NHL, but among the ancillary benefits has been the emergence of young players who apprenticed for an additional season in the minors … Michael Farber, Sports Illustrated, 21 Nov. 2005
I am in love with a man who is in love with boats. As far as ancillary loves are concerned, I understand things could be worse. Sadly, I do not love boats. Ann Patchett, Gourmet, May 2003
Traditionally museums have been built to house collections, and for ancillary functions such as storage, conservation, administration, and education. Jayne Merkel, Wilson Quarterly, Winter 2002
Paleolithic hunters and gatherers obtained an abundance of complete protein, mostly from wild game; their vegetable foods were an ancillary protein source. This pattern prevailed until agriculture transformed it, shifting the human diet away from meat and toward plant food. S. Boyd Eaton et al., The Paleolithic Prescription, 1988
The company hopes to boost its sales by releasing ancillary products.
Recent Examples on the Web Rebuilt in the mid-18th century, the building dates back to 1665 and was originally used as an ancillary accommodation for guests of King Charles II. Joanne Shurvell, Forbes, 28 Dec. 2022 Outside of that, Netflix will invest about $850 million in the production hub, with plans to build 12 sound stages, ancillary production support and a backlot. Caitlin Huston, The Hollywood Reporter, 21 Dec. 2022 Another eight apparatuses, required for ancillary vehicles and for training purposes will be bought via a funds from the town’s ARPA allocation for $105,082. Steve Smith, Hartford Courant, 6 Dec. 2022 After all, the costs of media inventory must be considered along with those of hiring an ad agency; doing deals with celebrities and musicians; creating special effects; and putting in place ancillary marketing efforts at retail outlets and on social media. Brian Steinberg, Variety, 7 Sep. 2022 Contemporary pro fighters in high-profile events often sport trunks festooned with sponsor logos, an important source of ancillary income. New York Times, 30 May 2022 As president, acquisitions and ancillary distribution at independent film company Bleecker Street, Kent Sanderson returns to the Croisette this year amid a recent box office rebound for tentpole releases. Mia Galuppo, The Hollywood Reporter, 16 May 2023 The business and ancillary businesses, this town, this state and tens of thousands will suffer tremendously. Ed Stockly, Los Angeles Times, 5 May 2023 Where the Miura has a simple, low dashboard showcasing a giant speedometer on the left, matching tachometer on the right, and ancillary gauges standing proud off to the side, the Countach jams everything into a traditional cluster behind the wheel. Tim Stevens, Robb Report, 4 May 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'ancillary.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


see ancilla

First Known Use

1663, in the meaning defined at sense 1

Time Traveler
The first known use of ancillary was in 1663

Dictionary Entries Near ancillary

Cite this Entry

“Ancillary.” Dictionary, Merriam-Webster, Accessed 7 Jun. 2023.

Medical Definition


1 of 2 adjective
ˈan(t)-sə-ˌler-ē, especially British an-ˈsil-ə-rē
: being auxiliary or supplementary
use of a drug as ancillary to surgical treatment
ancillary staff
ancillary diagnostic services


2 of 2 noun
plural ancillaries
British : one who assists or is supplementary to another person
: a supplemental diagnostic or therapeutic medical service (as magnetic resonance imaging or radiotherapy)

Legal Definition


: having a subordinate, subsidiary, or secondary nature
ancillary functions
an ancillary agreement
: serving as a supplement or addition
ancillary documents
: directly related
ancillary claims
Last Updated: - Updated example sentences
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