Naut. [f. JACK sb.1 33 + STAY.] a. A rope, rod or batten placed along a yard or gaff to bend the sail to. b. A rod or rope running up and down on a mast, on which the square-sail yard travels.
1840. R. H. Dana, Bef. Mast, Gloss., Jack-stays, ropes stretched taut along a yard, to bend the sail to.
c. 1860. H. Stuart, Seaman’s Catech., 19. What is the use of jackstays? To bend the sails to.
1875. Bedford, Sailor’s Pocket Bk., VI. (ed. 2), 227. A jackstay should be fitted round the boat, underneath the rubbing strake for the rain awning to be laced down to.
