the common ground or dwarf hemlock, a bitter, poisonous plant. The Hebrew rosh is rendered "hemlock" in two passages, (Hosea 10:4; Amos 6:12) but elsewhere "gall." [GALL] (It is possible that the plant is rather the poppy than an hemlock. --Cook.)
Smith’s Bible Dictionary
Hemlock
Smith’s Bible Dictionary, William Smith (1863). Public domain, from the CrossWire SWORD module.