The Sindarin name of the “kingsfoil” (LotR/864), a combination athae and lass, hence literally “✱healing leaf”.
Conceptual Development: ᴱN. athelas appeared in the margins of The Lay of Leithian from the 1920s next to the phrase “of all the herbs of healing chief” (LB/269), and it already had the form N. athelas when it first appeared in Lord of the Rings drafts of the 1940s (RS/190).
n.Bot.'King's foil'. Q. asea aranion. F athae, athe, lass