ROUMANIAN is a 9 letter word that starts with R.

1. \Rou*ma"ni*an\, a. [Written also {Rumanian}.] [From
   Roumania, the name of the country, Roumanian Rom[^a]nia, fr.
   Rom[^a]n Roumanian, L. Romanus Roman.]
   Of or pertaining to Roumania.
   
   

2. \Rou*ma"ni*an\, n.
   An inhabitant of Roumania; also, the language of Roumania,
   one of the Romance or Romanic languages descended from Latin,
   but containing many words from other languages, as Slavic,
   Turkish, and Greek.