Source : Webster's Revised Unabridged Dictionary (1913)

Boxhaul \Box"haul`\, v. t. [imp. & p. p. {Boxhauled}.] (Naut.)
   To put (a vessel) on the other tack by veering her short
   round on her heel; -- so called from the circumstance of
   bracing the head yards abox (i. e., sharp aback, on the
   wind). --Totten.