🔼The name Merab in the Bible
Merab is the oldest of two daughters of king Saul, the other is called Michal (1 Samuel 14:49). In one of his more generous moods (and right after hurling his spear at David) Saul promises Merab to David as wife (18:17). David plays timid and Merab goes to Adriel the Meholathite.
The day Merab marries Adriel, Saul promises his second daughter Michal to David. That marriage actually happens. Merab becomes the mother of five sons but there names are not mentioned in the Bible (2 Samuel 21:8 — the Hebrew has the name Michal here but that's commonly understood to be a scribal error, or else some poorly understood literary device. Merab, not Michal was married to Adriel, and Michal stayed childless — 2 Samuel 6:23; Read our article on the infallibility of the Bible).
When much later a three year famine strikes Israel, the men of Gibeon demand of king David the extradition of seven of Saul's descendants, to serve as a kind of bizarre human sacrifice (2 Samuel 21:8). David actually consents and gives them all five sons of Merab and Adriel, as well as Armoni and Mephibosheth the sons of Saul and Rizpah. All seven are hanged at Gibeah.
Merab was probably not the first mother to lose her five sons to the intrinsic madness of the human collective, and certainly not the last. In his famous letter to the widow Lydia Bixby, who was believed to had lost her five sons during the American civil war, president Lincoln wrote, "I pray that our Heavenly Father may assuage the anguish of your bereavement, and leave you only the cherished memory of the loved and lost, and the solemn pride that must be yours to have laid so costly a sacrifice upon the altar of freedom".
In which way the death of Merab's five sons was virtuous or even beneficial is hard to say. Whether the bereaved Merab was ever capable of feeling daughterly towards the God of David, the hallowed and beloved peace-king and man after the Lord's own heart (Acts 13:22), if even harder to estimate.
🔼Etymology of the name Merab
The name Merab most probably comes from the רבב root-group:
BDB Theological Dictionary disregards a possible derivation from the above root group and lists Merab without explanation as unconnected entity alphabetically under the letter mem. Perhaps this is technically the right thing to do, but to any Hebrew audience, the name Merab would have had to do with the verbs rabab and raba.
For a meaning of the name Merab, Jones' Dictionary of Old Testament Proper Names reads Multiplication. NOBSE Study Bible Name List reads Increase.