indigo

noun

in·​di·​go ˈin-di-ˌgō 

plural indigos or indigoes

1

: a deep reddish blue

2

: indigo plant

3

a

: a blue vat dye obtained from plants (such as indigo plants)

b

: the principal coloring matter C₁₆H₁₀N₂O₂ of natural indigo usually synthesized as a blue powder with a coppery luster

Examples of indigo in a Sentence

Recent Examples on the Web

Mark Ix, the mill’s director of North American marketing, said the system has a 98 percent indigo recovery rate and a 98 percent water recovery rate. —Angela Velasquez, Sourcing Journal, 14 Oct. 2025

To keep things interesting and stylish, go for subtly different shades—cherry red and olive green—and match them with jewel tones like indigo and sapphire. —Marilú Almaguer, Glamour, 11 Oct. 2025

Choose from six rich colorways, including brick red and indigo blue. —Shoko Wanger, Architectural Digest, 6 Oct. 2025

Red, orange, yellow, green, blue, indigo, violet and pink. —Kansas City Star, 4 Oct. 2025

Word History

Etymology

Italian dialect, from Latin indicum, from Greek indikon, from neuter of indikos Indic, from Indos India

First Known Use

1555, in the meaning defined at sense 3a

Phrases Containing indigo

• indigo bunting
• indigo plant
• indigo snake
• wild indigo

Rhymes for indigo

• afterglow
• akimbo
• albino
• aliquot
• allegro
• amigo
• apropos
• audio
• bungalow
• calico
• calypso
• cameo

Kids Definition

indigo

noun

in·​di·​go ˈin-di-ˌgō 

plural indigos or indigoes

1

: a blue dye made artificially and formerly obtained from plants and especially indigo plants

2

: a deep reddish blue

Etymology

from an Italian dialect word indigo "a blue dye from indigo plants," from Latin indicum (same meaning), derived from Greek indikos (adjective) "of or relating to India"; so called because the plant dye was first widely produced in India

Medical Definition

indigo

noun

in·​di·​go ˈin-di-ˌgō 

plural indigos or indigoes

1

a

: a blue dye obtained from indigo plants (as Indigofera tinctoria of Africa and India, I. anil of South America, and I. auriculata of Arabia and Egypt)

b

: the principal coloring matter C₁₆H₁₀N₂O₂ of natural indigo usually synthesized as a blue powder with a coppery luster

called also indigotin

2

: indigo plant