The story
From allo- + alantolactone.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: The sesquiterpenoid lactone (3aR,8aR,9aR)-5,8a-dimethyl-3-methylidene-4,6,7,8,9,9a-hexahydro-3aH-benzo[f][1]benzofuran-2-one Full definition →
From allo- + alantolactone.
Etymology from Wiktionary, CC BY-SA 4.0.