Source : Webster's Revised Unabridged Dictionary (1913)

Arthurian \Ar*thu"ri*an\, a.
   Of or pertaining to King Arthur or his knights. --J. R.
   Symonds.

         In magnitude, in interest, and as a literary origin,
         the Arthurian invention dwarfs all other things in the
         book.                                    --Saintsbury.

Source : WordNet®

Arthurian
     adj : of or relating to King Arthur and the Knights of the Round
           Table