The Collaborative International Dictionary of English v.0.48:

Verst \Verst\, n. [Russ. versta: cf. F. verste.]
   A Russian measure of length containing 3,500 English feet.
   [Written also werst.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Werst \Werst\ (w[~e]rst), n.
   See Verst.
   [1913 Webster]