What is indigo by the term …

Indigo is a type of blue dye that is generally used for coloring of cotton yarn that is used for production of denim cloth for blue jeans. Indigo is also used for dyeing wool and silk. Indigo was a natural dye which was extracted from plants but now it is synthetic. Indigo is an ancient dye and there is evidence for the use of indigo from woad or Indigofera from the third millennium BC, and possibly much earlier for woad. ... This is the largest known ancient civilization and at its peak may have supported a population of over 5 million inhabitants.

Indigo is an ancient dye and there is evidence for the use of indigo from woad or Indigofera from the third millennium BC, and possibly much earlier for woad. ... This is the largest known ancient civilization and at its peak may have supported a population of over 5 million inhabitants. The word indigo comes from the Latin for "Indian", as the dye was originally imported to Europe from India. Indigo is a type of blue dye that is generally used for coloring of cotton yarn that is used for production of denim cloth for blue jeans. Indigo is also used for dyeing wool and silk. Indigo was a natural dye which was extracted from plants but now it is synthetic.