backstay

noun

1. Machinery. a supporting or checking piece in a mechanism.
2. Building Trades. an anchored tension member, as a cable, permanently or temporarily supporting a compression member, as a tower or pole, subject to a pull above its base from the opposite direction.
3. a strip of leather at the back of a shoe used for reinforcement and sometimes to connect the quarters.

noun

1. Nautical. any of various shrouds forming part of a vessel’s standing rigging and leading aft from masts above a lower mast to the sides or stern of the vessel in order to reinforce the masts against forward pull.

noun

1. nautical a stay leading aft from the upper part of a mast to the deck or stern
2. machinery a supporting piece or arresting part
3. anything that supports or strengthens the back of something, such as leather covering the back seam of a shoe