ancillary

adjective

an·​cil·​lary ˈan(t)-sə-ˌler-ē 

-ˌle-rē,

 especially British  an-ˈsi-lə-rē

1

: subordinate, subsidiary

the main factory and its ancillary plants

2

: auxiliary, supplementary

the need for ancillary evidence

ancillary expenses

ancillary equipment

ancillary noun

Did you know?

If you’re already familiar with ancillary, pull up a chair and help yourself to a side dish of trivia. The word comes from the Latin word ancilla, meaning "a female servant," which also gave us the rarer English word ancilla, meaning "an aid to achieving or mastering something difficult." While the English ancilla (which made its debut a couple of centuries after ancillary) 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."

Examples of ancillary in a Sentence

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

Many of those shareholders are expected to be on the ground this week as the league prepares various ancillary events and activations. —Eric Jackson, Sportico.com, 23 Apr. 2025

And many of these ancillary tech gadgets appear to be from China. —Lisa Eadicicco, CNN Money, 16 Apr. 2025

Brand Identity The motivation behind these changes is clear: Southwest wants to boost revenue through ancillary fees and attract new customer segments. —Roger Dooley, Forbes, 11 Mar. 2025

If the spouse seeking to divorce failed to prove his or her cause of action, there could be no divorce granted and the ancillary issues could not be addressed by the Court. —Patricia Fersch, Forbes.com, 9 Apr. 2025

Word History

Etymology

see ancilla

First Known Use

1663, in the meaning defined at sense 1

Rhymes for ancillary

• accessary
• adversary
• arbitrary
• aviary
• axillary
• beriberi
• breviary
• budgetary
• capillary
• catenary
• cautionary
• cemetery

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Medical Definition

ancillary

1 of 2 adjective

an·​cil·​lary

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

ancillary

2 of 2 noun

plural ancillaries

1

British : one who assists or is supplementary to another person

2

: a supplemental diagnostic or therapeutic medical service (as magnetic resonance imaging or radiotherapy)

Legal Definition

ancillary

adjective

an·​cil·​lary ˈan-sə-ˌler-ē, an-ˈsi-lə-rē 

1

: having a subordinate, subsidiary, or secondary nature

ancillary functions

an ancillary agreement

2

: serving as a supplement or addition

ancillary documents

3

: directly related

ancillary claims