anovulatory drug vs birth control pill

anovulatory drug and birth control pill both are nouns.

Word	Noun	Adjective	Verb	Adverb
anovulatory drug	Yes	No	No	No
birth control pill	Yes	No	No	No

As nouns, anovulatory drug and birth control pill are synonyms defined as:

anovulatory drug and birth control pill: a contraceptive in the form of a pill containing estrogen and progestin to inhibit ovulation and so prevent conception

Other synonyms of anovulatory drug include anovulant, contraceptive pill, oral contraceptive, oral contraceptive pill, pill.

anovulatory drug (noun)	birth control pill (noun)
a contraceptive in the form of a pill containing estrogen and progestin to inhibit ovulation and so prevent conception	a contraceptive in the form of a pill containing estrogen and progestin to inhibit ovulation and so prevent conception