prophylaxis

noun

pro·​phy·​lax·​is ˌprō-fə-ˈlak-səs How to pronounce prophylaxis (audio)
 also  ˌprä-
plural prophylaxes ˌprō-fə-ˈlak-ˌsēz How to pronounce prophylaxis (audio)
 also  ˌprä-
: measures designed to preserve health (as of an individual or of society) and prevent the spread of disease

Did you know?

In Greek, phylax means "guard", so prophylactic measures guard against disease by taking action ahead of time. Thus, for example, before the polio vaccine became available, prophylaxis against polio included avoiding crowds and public swimming pools. These days a well-known kind of prophylactic is used to prevent sexually transmitted diseases; but prophylactic measures only work when people use them.

Examples of prophylaxis in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Similar algorithms have been developed in Kenya and Uganda to help determine ideal candidates for pre-exposure prophylaxis (PrEP). Jennifer Lotito, Forbes, 3 Oct. 2024 After infusion, 94% of patients in a trial no longer needed routine prophylaxis therapy. Web Golinkin, Forbes, 12 Sep. 2024 In June, the CDC recommended doxycycline post-exposure prophylaxis for high-risk groups — essentially, a morning after pill for STIs. Simar Bajaj, NBC News, 8 Sep. 2024 Teeth cleaning, also known as dental cleaning or dental prophylaxis, is when a dentist or dental hygienist thoroughly cleans your teeth, gums, and the inside of your mouth. Sherri Gordon, Health, 14 Aug. 2024 See all Example Sentences for prophylaxis 

Word History

Etymology

borrowed from New Latin, from Greek prophylak-, stem of prophylássein "to keep guard before a place, be on guard, (middle voice) to be on one's guard against, take precautions against" (from pro- pro- entry 1 + phylássein "to keep watch on, guard, preserve," derivative of phylak-, phýlax "guard, guardian, protector") + -sis -sis — more at phylactery

First Known Use

1683, in the meaning defined above

Time Traveler
The first known use of prophylaxis was in 1683

Dictionary Entries Near prophylaxis

Cite this Entry

“Prophylaxis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/prophylaxis. Accessed 21 Nov. 2024.

Medical Definition

prophylaxis

noun
pro·​phy·​lax·​is -ˈlak-səs How to pronounce prophylaxis (audio)
plural prophylaxes -ˈlak-ˌsēz How to pronounce prophylaxis (audio)
: measures designed to preserve health and prevent the spread of disease : protective or preventive treatment
prophylaxis against viral diseases
a paste containing fluorine for dental prophylaxis

More from Merriam-Webster on prophylaxis

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