indian
n. countablen. a person from India or someone whose family comes from there. It can also refer to a meal from an Indian restaurant, like a curry.
n. a person of Indian nationality or descent; also used metonymically in British English to refer to a meal from an Indian restaurant.
We are going out for an Indian tonight.
My neighbor is an Indian who moved here last year to work as a software engineer.
The local high street features several competing restaurants, but most residents agree that the small family-run Indian serves the most authentic regional cuisine.
From Anglo-Norman indien, Middle French indien, corresponding to Ind + -ian or India + -an. Applied to inhabitants of the Americas due to an early misconception that the Americas were the eastern end of Asia / the Indies (hence also the designation of Caribbean islands as the West Indies).
When referring to people, it is always capitalized. In the sense of a meal, it is an informal British usage.