• (a.) Pertaining to, or derived from, gallnuts or gallic acid; as, ellagic acid.
El·lag'ic adjective [ French, from galle gall (with the letters reversed).] (Chemistry) Pertaining to, or derived from, gallnuts or gallic acid; as, ellagic acid. Ellagic acid (Chemistry) , a white crystalline substance, C 14 H 8 O 9