prophylactic

American  

[proh-fuh-lak-tik, prof-uh-] / ˌproʊ fəˈlæk tɪk, ˌprɒf ə- /

adjective

1. defending or protecting from disease or infection, as a drug.

2. preventive or protective.

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noun

1. Medicine/Medical. a prophylactic medicine or measure.

2. a preventive.

3. a device, usually a rubber sheath, used to prevent conception or venereal infection; condom.

prophylactic British  

/ ˌprɒfɪˈlæktɪk /

adjective

1. protecting from or preventing disease

2. protective or preventive

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noun

1. a prophylactic drug or device, esp a condom

Other Word Forms

• prophylactically
  adverb

Etymology

Origin of prophylactic

First recorded in 1565–75; from Greek prophylaktikós “of guarding,” equivalent to prophylak- (base of prophylássein “to guard beforehand”) + -tikos -tic; see prophylaxis

Explanation

Prophylactic might sound like a prehistoric period when dinosaurs roamed the earth, but it actually describes something that can prevent something negative, such as disease. Prophylactic surgery to remove a mole can prevent skin cancer. If you want to avoid getting sick, you can get a vaccine, take medicine, or have surgery — all of which are considered prophylactic measures. Delve deeper into the history of this four-syllable word and you'll find the Greek term prophulaktikos, which means to "guard before." Prophylactic can also describe a contraceptive used to prevent pregnancy. This use of the word started because condoms, which are prophylactics, were originally designed to prevent disease, not pregnancy.

Example Sentences

See Examples For:

prophylactic

While experts try to lock in a diagnosis, the center reported she’s receiving several prophylactic treatments and they are “cautiously hopeful.”

From Los Angeles Times ● Jul. 28, 2026

Pet owners across the country have been advised they should treat their cats and dogs as a preventative measure every month, known as prophylactic use - although many veterinary organisations have now updated their advice.

From BBC ● Jun. 10, 2026

Doctors specializing in breast reconstruction say they are seeing ever-younger women opting to remove their breasts as a prophylactic measure.

From The Wall Street Journal ● Jun. 7, 2026

It also announced plans to buy Cidara Therapeutics, which is working on antiviral treatments, including a flu prophylactic in Phase 3, for $9.2 billion.

From MarketWatch ● Feb. 3, 2026

It is on account of this very insidiousness of onset that I have elsewhere urged as a prophylactic measure the examination every six months of all persons over forty years of age.

From Arteriosclerosis and Hypertension: with Chapters on Blood Pressure, 3rd Edition. by Warfield, Louis Marshall