Source : Webster's Revised Unabridged Dictionary (1913)

Rectrix \Rec"trix\ (-tr?ks), n.; pl. {Rectrices} (-tr?"s?z).
   [L., fem. of rector.]
   1. A governess; a rectoress.

   2. (Zo["o]l.) One of the quill feathers of the tail of a
      bird.