Acting to defend against or prevent something, especially disease; protective.(adjective)
A prophylactic agent, device, or measure, such as a vaccine or drug.(noun)
A contraceptive device, especially a condom.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "prophylactic" in a sentence
"Thirdly, if people are getting frequent attacks, there are what we call prophylactic, preventive drugs."
"And slightly later, I owe my gratitude to Al Lowe for teaching me, by way of Leisure Suit Larry, what a "prophylactic" is at the age of eight or so (yes, precocious, intellectual independence, hallelujah)!"
"Prophylactic The word prophylactic means preventive but condoms are sometimes called prophylactics."