All 4 Uses

Hinduism
in
Underworld, by DeLillo
(Auto-generated)

Go to the desert or tundra and wait for the visionary flash of light, the critical mass that will call down the Hindu heavens, Kali and Shiva and all the grimacing lesser gods.†

Hindu = someone who believes in Hinduism (the third most common religion--which has many gods and is associated with India)
Could just as easily be Oppenheimer and Teller, their bodies greased with suntan oil as they quote Hindu scriptures to each other.†
*
He stuck the rubber in his pocket, absently—he was wearing the same Nehru jacket he'd sported in San Francisco, his Hindu statesman number, and the thing was rutted and crushed by now, resembling some wadded discard plucked from the gutter.†
Many people had never heard these words spoken before an audience—by a guy in a Hindu tunic yet—and there was an odd turn of truth, a sense of unleashing perhaps, or disembarrassment.†

Definitions:

(1) (Hinduism)
the third most common religion; polytheistic (many gods) with most adherents in India

Only Christianity and Islam have more followers than Hinduism.
(2) (meaning too rare to warrant focus)