Cultural Hindus

A Cultural Hindu is a religiously unobservant individual who identifies with Hinduism, usually due to family background.

Definition
Emory University professor John Y. Fenton defines the locution as follows:

The term has come into vogue as a result of secularization. Cultural Hindus, while not religiously devout, may still observe Hindu festivals, such as Diwali. For these individuals, this commemoration of Hindu festivals, as well as occasional temple attendance, serve as a celebration of their heritage.