According to 1 Chronicles 20:5, what was the name of Goliath's brother, killed by Elhanan son of Jair?

Answer: Lahmi

Elhanan son of Jair killed Lahmi the brother of Goliath the Gittite, whose spear shaft was like a weaver's beam.

“Once again there was a battle with the Philistines, and Elhanan son of Jair killed Lahmi the brother of Goliath the Gittite, the shaft of whose spear was like a weaver’s beam.”— 1 Chronicles 20:5 (BSB)