jackstay
nounA stay for racing or cruising vessels used to steady the mast against the strain of the gaff.
nounA rope, rod, or batten along the upper side of a yard, gaff, or boom to which a sail is fastened.
nounA rope or rod running vertically on the forward side of the mast on which the yard moves.
nounNautical: One of a set of ropes, iron rods, or strips of wood attached to a yard or gaff for bending a square sail to.
nounA rod or rope running up and down on the forward side of a mast, on which the square-sail yard travels; a traveler.
nounA rail of wood or iron stretching along a yard of a vessel, to which the sails are fastened.
nounA