Dictionary.net

• Either half of a ship's yard, from the centre or mast to the end.

1914 - Nuttall's Standard dictionary of the English language
By Nuttall, P.Austin.

• One half of a ship's yard from the centre or mast to the end.

1874 - Etymological and pronouncing dictionary of the English language
By Stormonth, James, Phelp, P. H.