pig vs birth

pig and birth both are nouns.

Word	Noun	Adjective	Verb	Adverb
pig	Yes	No	Yes	No
birth	Yes	No	Yes	No

As verbs, birth is a hypernym of pig; that is, birth is a word with a broader meaning than pig:

Other hypernyms of pig include bear, deliver, give birth, have.

pig (noun)	birth (noun)
domestic swine	the event of being born
a crude block of metal (lead or iron) poured from a smelting furnace	a baby born; an offspring
mold consisting of a bed of sand in which pig iron is cast	the process of giving birth
a person regarded as greedy and pig-like	the kinship relation of an offspring to the parents
uncomplimentary terms for a policeman	the time when something begins (especially life)
a coarse obnoxious person