indigo UK /ˈɪn.dɪˌɡəʊ/US /ˈɪndɪˌɡoʊ/noun 4adjective 1forms 4 noun4 •A purplish-blue color. •A greenish dark blue color; the color of indigo dye. •A blue-colored dye obtained from certain plants (indigo plant or woad), or a similar synthetic dye. •An indigo plant, such as from species in genera Indigofera, Amorpha (false indigo), Baptisia (wild indigo), and Psorothamnus and Dalea (indigo bush).A Southern planter has been sowing indigo and cotton together. Perhaps he contemplates raising blue cotton; and should he water the plants with nitric acid, he would probably raise gun cotton—if any. — 1846 adjective1 •having a deep purplish-blue colour formsindigoes · indigos · more indigo · most indigo
