I. ˈində̇ˌgō, -dēˌ- noun
( plural indigos or indigoes )
Etymology: Italian indaco & Italian dialect (northern) indigo, endego, from Latin indicum, from Greek indikon, from neuter of indikos Indic — more at indic
1.
a. : a blue vat dye that was obtained originally from plants (as indigo plants or woad) by hydrolysis of the indican present and oxidation by air of the resulting indoxyl and that unless specially purified contained other substances (as indirubin) besides the principal coloring matter — called also natural indigo
b. or indigo blue : the principal coloring matter C 16 H 10 N 2 O 2 of natural indigo that is synthesized as a blue crystalline powder with a coppery luster usually by oxidation of synthetic indoxyl with air in the presence of alkali and that is used chiefly as a vat dye for cotton and wool — called also indigotin, synthetic indigo ; see dye table I (under Vat Blue 1 ); compare indigo white , structural formula
c. : any of several blue vat dyes derived from or closely related to indigo
2.
a. : indigo plant
b. : any of various plants resembling the indigo plant
3. or indigo blue : a variable color averaging a dark grayish blue that is redder and deeper than night blue — called also inde blue, Indian blue
II. adjective
or indigo-blue | ̷ ̷ ̷ ̷(ˌ) ̷ ̷| ̷ ̷
: being of the color indigo