Source : Webster's Revised Unabridged Dictionary (1913)

Cran \Cran\ (kr[a^]n), Crane \Crane\ (kr[=a]n), n. [Scot., fr.
   Gael. crann.]
   A measure for fresh herrings, -- as many as will fill a
   barrel. [Scot.] --H. Miller.

Source : WordNet®

cran
     n : a capacity unit used for measuring fresh herring