[proh-fuh-lak-sis, prof-uh-]


  1. the preventing of disease.
  2. the prevention of a specific disease, as by studying the biological behavior, transmission, etc., of its causative agent and applying a series of measures against it.
prophylactic treatment, as the cleaning of the teeth by a dentist or dental hygienist.

Origin of prophylaxis

1835–45; < New Latin < Greek pro- pro-2 + phýlaxis a watching, guarding, equivalent to phylak- (base of phylássein to guard) + -sis -sis Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for prophylaxis

sanitation, prevention, treatment

Examples from the Web for prophylaxis

Historical Examples of prophylaxis

  • The prophylaxis of yellow-fever is suggested by means of static electricity.

    Makers of Electricity

    Brother Potamian

  • Only in this way is the prophylaxis of arteriosclerosis possible.

    Arteriosclerosis and Hypertension:

    Louis Marshall Warfield

  • Undoubtedly the most important phase of it is in prophylaxis.


    James J. Walsh

  • Prophylaxis of the habit is an ethical question that we can scarcely do justice to here.


    James J. Walsh

  • In prophylaxis of the family the first indication is to stop the production of degenerates.


    Eugene S. Talbot

British Dictionary definitions for prophylaxis



the prevention of disease or control of its possible spread
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for prophylaxis

"preventive treatment of disease," 1746, Modern Latin, from Greek pro (see pro-) + phylaxis "a watching, guarding" (see prophylactic).

Online Etymology Dictionary, © 2010 Douglas Harper

prophylaxis in Medicine


[prō′fə-lăksĭs, prŏf′ə-]

n. pl. pro•phy•lax•es (-lăksēz′)

Prevention of or protective treatment for disease.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.