barrier methods meaning

• [Medicine]
  Methods of contraception in which physical,chemical,or biological means are used to prevent the SPERM from reaching the fertilizable OVUM.

• contraceptive barrier methods:    [Medicine]Methods ...
• contraceptive vaginal barrier methods:    [Medicine]Methods ...
• vaginal barrier methods:    [Medicine]Methods ...

Examples

1. Barrier methods constitute an alternative class of algorithms for constrained optimization.
2. Couples use condoms or barrier methods to prevent pregnancy on blue bead days.
3. Barrier methods have a risk of allergic reaction.
4. Barrier methods, coitus interruptus, and spermicides must be used at every act of intercourse.
5. Nor were barrier methods of contraception.