A.T. Robertson Commentary Mark 3:17

"and James the [son] of Zebedee, and John the brother of James; and them he surnamed Boanerges, which is, Sons of thunder:" — Mark 3:17 (ASV)

Boanerges, which is Sons of thunder (Βοανηργες ο εστιν υιο βροντης). This Hebrew nickname is given only by Mark and the reason for it is not clear. It may refer to the fiery temperament revealed in Lu 9:34 when James and John wanted to call down fire on the Samaritan villages that were unfriendly to them. The word literally means

sons of tumult, sons of thunder in Syriac. No other epithets are given by Mark save descriptions to distinguish as Simon the Cananaean (or Zealot) and Judas Iscariot, who also betrayed him (verse 19). Andrew, (from ανηρ, a man) and Philip (Philippos, fond of horses) are both Greek names. Bartholomew, son of Tolmai, is the Nathanael of John's Gospel (John 21:2). He probably had both names. Matthew is a Hebrew name meaning gift of God (Μαθθαιος). Thomas is Hebrew and means Twin (Didymus, John 11:16). There are two uses of the name of James (Ιαχωβος, Jacob). Thaddeus is another name for Lebbaeus.