As a kid, I was intriguied to see janatha pronouncing the name of Jesus differently. kannaDigas would call him "yEsu" and we would read "Jesus" in English. It was not at all very difficult to know the details/etymology, as Jesus is so revered by so many janatha.
Note: I have tried to write all names below phonetically. More like ITRANS encoding. So it might spell different than the conventional spellings.
I later on found out what is Jesus called in many langages:
Step 2: The word "Yesus" is derived from the word iEsous in Greek. Greek nouns which are prathama vibhakti pullinga (nominative case of male nouns), tend to end with a an 's' sound. This is similar to the same in Sanskrit - ref - pANini sUtras on noun cases.
Step 3: The Greek word Iesous is derived from the Aramaic name of Jesus - yEsu, or the Hebrew name yEshu.
Step 4: The Aramaic name yEsu is actually a colloqual form of the Hebrew word yOshua. Named after Yoshua - the successor of Moshe as leader of the Hebrew people.
Step 5: Yoshua actually means "Yahweh is salvation" in Hebrew. See about Yahweh below from a dictionary.
YAHWEH (m) A name of the Hebrew God, represented in Hebrew by the tetragrammaton ("four letters") Yod He Waw He, transliterated into Roman script Y H W H. Because it was considered blasphemous to utter the name of God it was only written and never spoken. This resulted in the original pronunciation being lost. The name may have originally been derived from the old Semitic root hwy meaning "to be, to become".