Definition of "prophylactic" [proph•y•lac•tic]

• 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.

• "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."