Gulgoleth is the Hebrew word for “skull.”  In the OT, the word is used several times in contexts where people are being counted “skull by skull” (Exodus 16:16; 38:26; Numbers 1:2, 18, 20, 22; 3:47).

More interesting for interpreting Matthew are several occurrences of the word in narratives.  Abimelech’s skull is crushed by a millstone dropped from a tower (Judges 9:53), after the dogs get through with her only Jezebel’s hands and skull remain (2 Kings 9:35), and the Philistines take the skull of Saul and pin it up on display in the temple of Dagon (1 Chronicles 10:10).

Obviously, these incidents reach back to Genesis 3: These are all forms of the serpent whose skulls are crushed or whose heads are removed from their bodies.  Two false kings (the first two false kings, Abimelech and Saul, whose stories are closely parallel) and one false queen (the first false queen in Israel’s history), the prototype of the harlot bride.  Jesus is the true king of Israel, but He dies at a place reminiscent of the deaths of Israel’s tyrants and whores.  He dies at the place where heads are crushed, where heads are severed; He is the crushed Head severed from His body, who receives the death blow but then revives.