Morning-after pill and Preventative

Morning-after pill noun - A large dose of estrogen taken orally within 24 to 72 hours after intercourse; prevents implantation of a fertilized ovum and so acts as a contraceptive; commonly used after rape or incest.

Preventative and morning-after pill are semantically related. In some cases you can use "Preventative" instead a noun phrase "Morning-after pill".

Preventative noun - Any obstruction that impedes or is burdensome.

Morning-after pill and preventative are semantically related. Sometimes you can replace phrase "Morning-after pill" with "Preventative", this terms are similar.