Albert Barnes Commentary 1 Chronicles 2:7

"And the sons of Carmi: Achar, the troubler of Israel, who committed a trespass in the devoted thing." — 1 Chronicles 2:7 (ASV)

The name “Achan” (Joshua 7:1) appears to have been changed to “Achar” to more closely assimilate it with the Hebrew word for “troubler.” From the time of his sin, this was regarded as the true meaning of his name (Joshua 7:25–26).