The Collaborative International Dictionary of English v.0.48:

Uphroe \U"phroe\, n. (Naut.)
   Same as Euphroe.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

euphroe \eu"phroe\, n. [Etymol. uncertain.]
   A block or long slat of wood, perforated for the passage of
   the crowfoot, or cords by which an awning is held up.
   [Written also uphroe and uvrou.] --Knight.
   [1913 Webster]