in·​cus ˈiŋ-kəs How to pronounce incus (audio)
: the middle bone of a chain of three small bones in the ear of a mammal

called also anvil

see ear illustration

Example Sentences

Recent Examples on the Web The smallest bones are inside your ear, and they are known as the hammer (malleus), stirrup (stapes), and anvil (incus). Jason Bittel, Washington Post, 20 Oct. 2019 The auditory ossicles of the middle ear – the malleus, incus and stapes – are the tiniest bones in the human body. Emily Matchar, Smithsonian, 18 Dec. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'incus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


borrowed from New Latin incūd-, incūs, going back to Latin, "anvil," from in- in- entry 2 + -cūd-, -cūs, root noun from the stem of cūdere "to beat, strike, hammer" — more at hew

Note: The Latin name incūs "anvil" was first applied to the bone from its resemblance to an anvil by Andreas vesalius, in De humanis corporis fabrica libri septem (Basil, 1543), pp. 34-35; for details see C.D. O'Malley and Edwin Clarke, "The discovery of auditory ossicles," Bulletin of the History of Medicine, vol. 35, no. 5 (September-October, 1961), pp. 419-41. Regarding the semantic structure of the compound incūs, see note at anvil.

First Known Use

1615, in the meaning defined above

Time Traveler
The first known use of incus was in 1615

Dictionary Entries Near incus

Cite this Entry

“Incus.” Dictionary, Merriam-Webster, Accessed 29 Jan. 2023.

Kids Definition


in·​cus ˈiŋ-kəs How to pronounce incus (audio)
plural incudes iŋ-ˈkyüd-(ˌ)ēz How to pronounce incus (audio)

Medical Definition


in·​cus ˈiŋ-kəs How to pronounce incus (audio)
: the middle bone of the chain of three ossicles in the middle ear of a mammal resembling a premolar tooth with the body having a facet which articulates with the malleus and with the longer of the two widely separated crura having a process which articulates with the stapes

called also ambos, anvil

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