hy·​per·​ker·​a·​to·​sis ˌhī-pər-ˌker-ə-ˈtō-səs How to pronounce hyperkeratosis (audio)
plural hyperkeratoses ˌhī-pər-ˌker-ə-ˈtō-ˌsēz How to pronounce hyperkeratosis (audio)
: hypertrophy of the corneous layer of the skin
hyperkeratotic adjective

Examples of hyperkeratosis in a Sentence

Recent Examples on the Web Roughly 40% of dogs suffer from paw pad hyperkeratosis, a condition characterized by thickened and hardened paw pads. Amber Smith, Discover Magazine, 5 Nov. 2023 An infected frog then develops hyperkeratosis, a thickening of the keratin layer of the skin that inhibits water and oxygen from being absorbed. Rachel Crowell, Quanta Magazine, 17 Apr. 2023 Not only can weather changes and hyperkeratosis affect your pooch’s paws, but these conditions can affect their noses as well. Nicole Forsyth, The Mercury News, 5 Sep. 2019 Or your dog may have a genetic condition called hyperkeratosis that makes their paws and noses vulnerable to becoming dry. Nicole Forsyth, The Mercury News, 5 Sep. 2019 Soften Up Don’t overlook the rest of your hands: Rough patches on the palms can be remedied using a callus softener like Deborah Lippmann’s Get Off, which uses lactic acid to break down hyperkeratosis (thickening of the skin). Donna Bulseco, WSJ, 2 May 2018

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

Word History


earlier as a name for keratoconus (conical distortion of the cornea), borrowed from New Latin (in a German context), from hyper- hyper- + Greek kerat-, kéras "horn" + New Latin -osis -osis — more at kerato-

Note: As an ophthalmological term introduced by the German ophthalmologist Karl Himly (1772-1837) in Bibliothek für Ophthalmologie, 1. Band, 2. Stück (Hannover, 1819), p. 401.

First Known Use

1841, in the meaning defined above

Time Traveler
The first known use of hyperkeratosis was in 1841

Dictionary Entries Near hyperkeratosis

Cite this Entry

“Hyperkeratosis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/hyperkeratosis. Accessed 29 May. 2024.

Medical Definition


hy·​per·​ke·​ra·​to·​sis -ˌker-ə-ˈtō-səs How to pronounce hyperkeratosis (audio)
plural hyperkeratoses -ˈtō-ˌsēz How to pronounce hyperkeratosis (audio)
: hypertrophy of the stratum corneum layer of the skin
: any of various conditions marked by hyperkeratosis
: a disease of cattle that is marked by thickening and wrinkling of the hide, by formation of papillary outgrowths on the buccal mucous membranes, and often by a watery discharge from eyes and nose, diarrhea, loss of weight, and abortion of pregnant animals and that is caused especially by ingestion of the chlorinated naphthalene of various lubricating oils, by arsenic poisoning, or by inherited congenital ichthyosis

called also X-disease, XX disease

hyperkeratotic adjective

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