An Arvanite is a member of a population group of Greece who traditionally speak Arvanitika, a dialect of Albanian, who settled in Greece during the late Middle Ages.

There is one OFFICIAL language... Greek. But there are fourteen languages spoken (signed, in the case of GSL) in Greece today:

Living: (12 Listed)

Albanian (Arvanitika)

Albanian (Tosk)

Bulgarian

Greek

Greek Sign Language

Pontic

Romanian (Balkan)

Romanian (Macedo)

Romanian (Megleno)

Romano-Greek

Slavic

Turkish

Dead:

Greek (Ancient)

Cappadocian Greek

Sources:

http://www.ethnologue.com/show_country.asp?name=GR