Onesiphorus was an early Christian mentioned in the Christian New Testament. A quick search of
http://bible.gospelcom.net/bible brought up the following verses:
2 Timothy 1
15
You know that everyone in the province of Asia has deserted me, including Phygelus and Hermogenes.
16
May the Lord show mercy to the household of Onesiphorus, because he often refreshed me and was not ashamed of my chains.
17
On the contrary, when he was in Rome, he searched hard for me until he found me.
*Hitchcock's Bible Names Dictionary* claims that the name "Onesiphorus" means: "who brings profit".
Since Onesiphorus is obviously a Greek name, we'll have to wait until our resident Greek -- Pavlos -- signs on, to give you a more thorough etymology of that name.
-- Nanaea