How did Lithuania get its name?

Scientists aren't sure so far, but there are some theories. "Lietuva" reffer to:
  • Litovnija - the land of seaside translated from (I don't know) language
  • Litus - seaside
  • Lietuva - lėtųjų kraštas - Lithuania is the land of slower ones
  • Lietava - the river in Lithuania
  • Lietis - join, unite
  • Lietuva - there was a soldiery