Definition of "prophylactic"

A medicine which preserves or defends against disease; a preventive.

1. (US, specifically) A prophylactic condom.  quotations  examples

   Quotations

   • It is not clear whether such education is to be directed to homosexuals (for whom prophylactics are not a contraceptive) or to heterosexuals as well (for whom prophylactics are a contraceptive).

     1977, Human Life Center, International Review of Natural Family Planning, Human Life Center, St. John's University, page 2

   • Given the widespread use of coitus interruptus and male prophylactics as contraceptive practices in France […]

     1994, Mary Louise Roberts, Civilization Without Sexes: Reconstructing Gender in Postwar France, 1917–1927, University of Chicago Press, page 96

   • Some men put the prophylactic on just the tip of the penis: this is a mistake, because the prophylactic will come off.

     2000, Peter Parnell, John Irving, The Cider House Rules: Here in St. Cloud's, Dramatists Play Service, Inc., page 46

(figuratively) Any device or mechanism intended to prevent harmful consequences.  examples

Serving to prevent or protect against an undesired effect, especially disease or pregnancy  examples