os·​si·​fy | \ ˈä-sə-ˌfī How to pronounce ossify (audio) \
ossified; ossifying

Definition of ossify

intransitive verb

1 : to change into bone The cartilages ossified with age.
2 : to become hardened or conventional and opposed to change so easy for the mind to ossify and generous ideals to end in stale platitudes— John Buchan

transitive verb

1 : to change (a material, such as cartilage) into bone ossified tendons of muscle
2 : to make rigidly conventional and opposed to change ossified institutions ossified ideologies

Did you know?

The skeletons of mammals originate as soft cartilage that gradually transforms into hard bone (in humans, the process begins in the womb and continues until late adolescence). This bone-building process has been called ossification since the late 17th century, and the verb ossify arrived soon after the noun. Both terms have come to refer to figurative types of hardening, such as that of the heart, mind, or soul. The words come from the Latin root os, meaning "bone." Os has also entered English as a synonym of bone in scientific contexts.

What is the difference between ossify and calcify?

Medically speaking, ossify refers to the process by which bone forms, or by which tissue (usually cartilage) changes into bone. Ossification is a natural process that starts in utero and which comprises several different steps—one of which is the deposit of calcium salts, also known as calcification. Calcify, however, only refers to the deposit of calcium salts in soft tissue and is not synonymous with ossify. Ossification creates bone tissue, which is more than simply a deposit of calcium salts.

Both ossify and calcify have gained more general uses as well. Calcify refers to hardening, to becoming inflexible and unable to change:

What were once upstart revisionist currents calcified into self-regarding academic sub-specialties, sponsoring plenty of analysis but little fundamental debate.
— Sean Wilentz, The New Republic, 2 July 2001

Ossify refers to becoming inflexible, conventional, and resistant to change:

For these writers, the ossified ideologies of the world, imbedded in the communal imagination, block vision, and as artists they respond not by criticism from without but by confrontation from within.
—Robert Coover, The New York Times Book Review, 18 Mar. 1984

While ossify generally has a slightly more disparaging connotation to it than calcify does in general uses, our evidence shows that the two words are beginning to merge semantically.

Examples of ossify in a Sentence

The cartilage will ossify, becoming bone. a disease that ossifies the joints
Recent Examples on the Web At the end of the summer, the antlers ossify, and elk scrape the velvet off on trees. The New Yorker, 7 Mar. 2022 While that belief is beginning to ossify among Republicans, a divide is brewing over Trump’s role in the party. Bryan Schott, The Salt Lake Tribune, 13 Sep. 2021 Nadal, who has a longstanding foot problem because his navicular bone did not correctly ossify during childhood, was upbeat about his progress after his loss to Harris. Ben Rothenberg, New York Times, 12 Aug. 2021 But: There is a risk that over time a firm’s social capital erodes, creativity flags, hierarchies ossify and team spirit fades, as Mr Hastings fears. Daniel Tenreiro, National Review, 16 Sep. 2020 Revelations that at first seemed fatally poisonous to the presidency gradually ossified in Washington’s atmosphere. Washington Post, 6 Feb. 2020 But once a baby takes its first breaths, its bone-forming cells are hard at work to ossify that cartilage—or turn it into sturdier bone—and join all the pieces together. Alex Schwartz, Popular Science, 5 Feb. 2020 What started in part as an effort in 1958 to break up cop and firefighter unions in Charlotte soon ossified into a state law covering all public employees. Nick Martin, The New Republic, 31 Jan. 2020 Unlike many people of their generation, Helen and Brice have not ossified in their emeritus years. Douglas Friedman, Town & Country, 22 Oct. 2018 See More

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

First Known Use of ossify

1699, in the meaning defined at transitive sense 1

History and Etymology for ossify

Latin oss-, os + English -ify

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Cite this Entry

“Ossify.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ossify. Accessed 26 Jun. 2022.

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More Definitions for ossify


os·​si·​fy | \ ˈäs-ə-ˌfī How to pronounce ossify (audio) \
ossified; ossifying

Medical Definition of ossify

intransitive verb

: to form or be transformed into bone cartilage ossified postnatally

transitive verb

: to change (as cartilage) into bone osteoblasts ossify the tissue

More from Merriam-Webster on ossify

Thesaurus: All synonyms and antonyms for ossify


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