The Hebrew noun anak refers to a plumb line — a weighted cord used by builders to ensure vertical alignment. It appears almost exclusively in Amos 7:7–8, where God uses the image to declare His standard of judgment against Israel. The word may derive from a root related to lead (the metal) or to pressing down.
In Amos 7:7–8, God stands beside a wall built with a plumb line, holding a plumb line in His hand. He declares He is "setting a plumb line" among His people Israel — meaning He is measuring them against His perfect standard of justice and righteousness. The image is devastating: Israel, built straight at Sinai, had curved and warped from God's standard. Anak thus becomes a symbol of divine evaluation and the inescapability of God's righteous measurement.