Hinduism vs religion

Hinduism and religion both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hinduism	Yes	No	No	No
religion	Yes	No	No	No

As nouns, religion is a hypernym of Hinduism; that is, religion is a word with a broader meaning than Hinduism:

Hinduism: a body of religious and philosophical beliefs and cultural practices native to India and based on a caste system; it is characterized by a belief in reincarnation, by a belief in a supreme being of many forms and natures, by the view that opposing theories are aspects of one eternal truth, and by a desire for liberation from earthly evils
religion: a strong belief in a supernatural power or powers that control human destiny

Other hypernyms of Hinduism include faith, religious belief.

As nouns, religion is a hypernym of Hinduism; that is, religion is a word with a broader meaning than Hinduism:

Hinduism: the religion of most people in India, Bangladesh, Sri Lanka, and Nepal
religion: an institution to express belief in a divine power

Other hypernyms of Hinduism include faith, organized religion.

Hinduism (noun)	religion (noun)
a body of religious and philosophical beliefs and cultural practices native to India and based on a caste system; it is characterized by a belief in reincarnation, by a belief in a supreme being of many forms and natures, by the view that opposing theories are aspects of one eternal truth, and by a desire for liberation from earthly evils	a strong belief in a supernatural power or powers that control human destiny
the religion of most people in India, Bangladesh, Sri Lanka, and Nepal	an institution to express belief in a divine power