Barnabas = "son of rest"
1) the surname of Joses or Joseph, a Levite, a native of Cyprus He was a distinguished Christian teacher and companion and colleague of Paul.
Part of Speech: noun proper masculine
Of Chaldee origin [H1247] and [H5029]; son of Nabas (that is, prophecy); Barnabas, an Israelite: - Barnabas.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root Βαρναβᾶς; click on the second column to search for that grammatical form of the root Βαρναβᾶς; click on the third column to search for that word and grammatical form; click on the total to search for the root Βαρναβᾶς.