v. To bring a square-rigged ship onto a new tack by hauling back the foresails whilst steering hard round
the GNU version of the Collaborative International Dictionary of English
v. 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).
The Century Dictionary and Cyclopedia
to veer (a ship) round on her heel when it is impracticable to tack.