orchil

• archil, archall, orchel, orchal

From Old French orchel, orseil (modern French orseille), of uncertain origin.

orchil (countable and uncountable, plural orchils)

1. Any of several lichens, especially those of the genera Roccella and Lecanora.
2. The purple dye, orcein, extracted from them (especially Lecanora tartarea) and often used as substitute for Tyrian purple.

• (lichen): orchella weed, archil lichen
• (dye): lacmus, orcein

• cudbear

• Orcein on Wikipedia.Wikipedia
• William Dwight Whitney, Benjamin E[li] Smith, editors (1911), “orchil”, in The Century Dictionary […], New York, N.Y.: The Century Co., →OCLC.
• “orchil”, in OneLook Dictionary Search.