from Skt., hind: India
An almost outdated and all too general term that often indicates little more than that a certain school of thought has come forth out of India (Persian Hind), a country that virtually teems with different religious systems, movements, and schools.
Using the term Hindu to describe a person's religious affiliation indicates mainly that she or he does not belong to one of the other religions existing in India: Jaina, Buddhism, Islam, Sikhism (or Christianity); to name but the major ones.
Today, the major traditions of Hindu worship are known as Shaiva (centered on the god Shiva), Vaishnava (centered on the god Vishnu), Shakta, and Tantra.
Historically speaking, so-called Hinduism also embraces what is known as Vedanta, a school of thought based on the ancient Vedas, which arose at the time of India being invaded by Indo-Europeans - if the Aryan Invasion Theory is true.
Sometimes, this classical Vedic Hinduism is referred to as Brahmanism, a name based on the name of the absolute (Skt., brahman) as well as on the highest caste; the priests known as Brahmin.
For the major 'Hindu' scriptures see Vedas, Upanishads, Puranas, Brahmanas.