Definition of "indigo" in English

noun

1. A purplish-blue color.

2. An indigo-colored dye obtained from certain plants (indigo plant or woad), or a similar synthetic dye.

3. An indigo plant, such as from species in genera Indigofera, Amorpha (false indigo), Baptisia (wild indigo), and Psorothamnus and Dalea (indigo bush).

adjective

1. having a deep purplish-blue colour