WEATHERCOCK is a 11 letter word that starts with W.

1. \Weath"er*cock`\, n.
   1. A vane, or weather vane; -- so called because originally
      often in the figure of a cock, turning on the top of a
      spire with the wind, and showing its direction. ``As a
      wedercok that turneth his face with every wind.''
      --Chaucer.
   
            Noisy weathercocks rattled and sang of mutation.
                                                  --Longfellow.
   
   2. Hence, any thing or person that turns easily and
      frequently; one who veers with every change of current
      opinion; a fickle, inconstant person.
   
   

2. \Weath"er*cock`\, v. t.
   To supply with a weathercock; to serve as a weathercock for.
   
         Whose blazing wyvern weathercock the spire. --Tennyson.