And Esau said to Jacob, “Please let me have a mouthful of that [a]red stuff there, for I am exhausted.” Therefore he was called [b]Edom by name.
Genesis 25:30 (NASB)
[a] Lit the red, this red
[b] I.e. red
The shared root is א-ד-מ (A-D-M), and it carries the meaning of earth, flesh, red, blood.
We've learned that the earth is cursed (Gen 3: the Fall), and that all flesh is doomed to die (Gen 7: the Flood)…
So when we encounter a man whose very name links back to earth and flesh and blood, we should know that a picture is being painted of what this man is like. This man represents the curse.
Jacob represents his opposite.