Albert Barnes Commentary 1 Samuel 18:19

"But it came to pass at the time when Merab, Saul`s daughter, should have been given to David, that she was given unto Adriel the Meholathite to wife." — 1 Samuel 18:19 (ASV)

Adriel the Meholathite - The five sons of this marriage perished at the hands of the Gibeonites (as noted in a marginal reference), where we also learn that Adriel’s father, or ancestor, was Barzillai. His birthplace was Meholah, probably the same as Abel-Meholah (see the note on 1 Kings 19:16).