SONNETEER is a 9 letter word that starts with S.

1. \Son`net*eer"\, n.
   A composer of sonnets, or small poems; a small poet; --
   usually in contempt.
   
         What woful stuff this madrigal would be In some starved
         hackney sonneteer or me!                 --Pope.
   
   

2. \Son`net*eer"\, v. i.
   To compose sonnets. --Lowell.