orchil

• archil, archall, orchel, orchal

From Middle English orchell, from Old French orchel, orseil, from Old Catalan orxella (influenced by dialectal Arabic [script needed] ('urjālla)), from Italian oricello, from Latin ōricilla, diminutive of ōricula (variant of auricula), both diminutives of auris (“ear”)) + illa (a double diminutive suffix) or from auris (“ear”) + cula + illa. The name of the dye was influenced by the visual resemblance of the lichen used in production to a small ear.

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.
• "orchil" in The American Heritage Dictionary of the English Language, Fifth Edition.