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

The brand debuted its first-ever women’s denim collection this month, offering a vintage wide-leg jean and an oversize denim jacket in bone and light indigo washes. —Angela Velasquez, Sourcing Journal, 24 Mar. 2026

From the top of Siberia Bowl, Lake Tahoe reflected a shade of deep indigo that matched the sky overhead. —Gregory Thomas, San Francisco Chronicle, 21 Mar. 2026

In exchange, India exported commodities like cotton cloth, indigo, silk, sugar, slaves, spices, and medicines, including opium. —Livia Gershon, JSTOR Daily, 20 Mar. 2026

In this case, relaxed white jeans—instead of the usual blue or indigo—brighten up a dark palette. —India Roby, Glamour, 17 Mar. 2026

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. suffruticosa of South America, and I. arrecta 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