Concise Bible Dictionary:

This name, signifying “sons of thunder,” was given by the Lord to James and John the sons of Zebedee (Mark 3:1717And James the son of Zebedee, and John the brother of James; and he surnamed them Boanerges, which is, The sons of thunder: (Mark 3:17)), perhaps because of their urgent zeal, as was manifest when, indignant at the treatment of their Lord, they asked if they should call down fire from heaven (Luke 9:5454And when his disciples James and John saw this, they said, Lord, wilt thou that we command fire to come down from heaven, and consume them, even as Elias did? (Luke 9:54)). It was John who told the Lord that they had forbidden one who was casting out demons in His name, because he followed not with them (Mark 9:3838And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us. (Mark 9:38)). This act of the apostles was condemned by the Lord, but it is to be feared that similar prohibition has often been repeated by others since those days.

Strong’s Dictionary of Greek Words:

of Chaldee origin (1123 and 7266); sons of commotion; Boanerges, an epithet of two of the apostles
KJV Usage:

Jackson’s Dictionary of Scripture Proper Names:

sons of thunder

Potts’ Bible Proper Names:

Sons of thunder, or commotion:―a name applied to James and John, Mark 3:17. {Filii tonitrui}