Albert Barnes Commentary 2 Samuel 2:16

"And they caught every one his fellow by the head, and [thrust] his sword in his fellow`s side; so they fell down together: wherefore that place was called Helkath-hazzurim, which is in Gibeon." — 2 Samuel 2:16 (ASV)

Compare Livy’s history of the battle between the Horatii and Curiatii. This combat, like that one, may have been proposed as a way to avoid the bloodshed of two nations united by kinship and having a common, powerful enemy in the Philistines.

Helkath-hazzurim - that is, “the part, field, or plot of the sharp edges or blades” . This seems, on the whole, the best explanation of this rather obscure name.