The Collaborative International Dictionary of English v.0.48:

Savior \Sav"ior\ (s[=a]v"y[~e]r), n. [OE. saveour, OF. salveor,
   F. sauveur, fr. L. salvator, fr. salvare to save. See Save,
   v.] [Written also saviour.]
   1. One who saves, preserves, or delivers from destruction or
      danger.
      [1913 Webster]

   2. Specifically: The (or our, your, etc.) Savior, he who
      brings salvation to men; Jesus Christ, the Redeemer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Saviour
    n 1: a teacher and prophet born in Bethlehem and active in
         Nazareth; his life and sermons form the basis for
         Christianity (circa 4 BC - AD 29) [syn: Jesus, Jesus of
         Nazareth, the Nazarene, Jesus Christ, Christ,
         Savior, Saviour, Good Shepherd, Redeemer,
         Deliverer]
    2: a person who rescues you from harm or danger [syn: savior,
       saviour, rescuer, deliverer]

Easton's 1897 Bible Dictionary:

Saviour
   one who saves from any form or degree of evil. In its highest
   sense the word indicates the relation sustained by our Lord to
   his redeemed ones, he is their Saviour. The great message of the
   gospel is about salvation and the Saviour. It is the "gospel of
   salvation." Faith in the Lord Jesus Christ secures to the sinner
   a personal interest in the work of redemption. Salvation is
   redemption made effectual to the individual by the power of the
   Holy Spirit.