·noun The wood or timber of the hemlock tree.
II. Hemlock ·noun An evergreen tree common in North America (Abies, / Tsuga, Canadensis); hemlock spruce.
III. Hemlock ·noun The name of several poisonous umbelliferous herbs having finely cut leaves and small white flowers, as the Cicuta maculata, bulbifera, and virosa, and the Conium maculatum. ·see Conium.