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

From her hospital admission to her death, Glasgow-born Lady Joan did not receive any prophylactic anticoagulation, which is used to stop blood clots from forming.

From BBC ● Sep. 9, 2026

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

She said she has seen a 30% increase in women ages 30 to 35 coming in for reconstruction after prophylactic mastectomies in the past three years.

From The Wall Street Journal ● Jun. 7, 2026

Along with routine screening through mammography or MRI, some individuals with inherited genetic mutations that greatly increase breast cancer risk may choose preventive surgery, including prophylactic mastectomy.

From Science Daily ● Jun. 6, 2026

Of zinc, as a prophylactic tonic in cardiac neuralgia, I know but little.

From Neuralgia and the Diseases that Resemble it by Francis E. Anstie