'archil' originates from Medieval Latin 'orchella' (and Old French 'orchil'), ultimately from a Romance/Medieval source referring to the lichen used for purple dye; the exact earlier origin is uncertain.

'archil' changed from Medieval Latin 'orchella' into Old French 'orchil' (also seen as 'archil') and was borrowed into modern English as 'archil' or 'orchil'.

Initially it referred to the lichen and the purple dye produced from it; over time the word remained associated with that dye but became more specialized and less common in everyday language.