From the Syriac Peshitta "Son of Thunder" reads "bar-rğešy"
The plural "Sons of Thunder" is read as Boanerges (bnê'-rğaš) (Βοανηργες)
And James, the son of Zebedee, and John, the brother of James, and he gave them the name Boanerges, which is Sons of Thunder.
Jesus surnames the brothers James and John to reflect their impetuosity. The Greek rendition of their name is Βοανηργες (Boanērges).
There has been much speculation about this name. Given the Greek translation that comes with it ('Sons of Thunder'), it seems that the first element of the name is 'bnê', 'sons of' (the plural of 'bar'), Aramaic (בני). This is represented by βοανη (boanê), giving two vowels in the first syllable where one would be sufficient. It could be inferred from this that the Greek transliteration may not be a good one. The second part of the name is often reckoned to be 'rğaš' ('tumult') Aramaic (רגיש), or 'rğaz' ('anger') Aramaic (רגז). Maurice Casey, however, argues that it is a simple misreading of the word for thunder, 'r`am' (due to the similarity of s to the final m). This is supported by one Syriac translation of the name as 'bnay ra`mâ'. The Peshitta reads "bnay rğešy," which would fit with a later composition for it, based on a Byzantine reading of the original Greek.