The Hebrew word rosh in this specialized usage (H7219, distinct from H7218 meaning 'head') refers to a poisonous plant or its bitter, toxic extract — often translated as 'gall,' 'poison,' or 'venom.' It appears in Deuteronomy 29:18 as a 'root that bears gall and wormwood,' symbolizing the toxic fruit of idolatry.
The bitter poison rosh serves as a powerful metaphor for the deadly consequences of covenant betrayal and sin. Deuteronomy warns that idolatry produces a 'root bearing gall and wormwood' — sweet-seeming in the moment but spiritually toxic. Jeremiah uses the image of 'water of gall to drink' as the judgment on unfaithful Israel. Most poignantly, Matthew 27:34 records that Jesus was offered wine mixed with gall at Golgotha — the bitter draught fulfilling Psalm 69:21. The one who bore our sin tasted our poison so that we might receive sweetness.