The Bitter End
This one seems pretty simple to explain really. “Bitter” has been used as a word to denote unpleasant or harsh for centuries, so it could simply be literal. But one camp of nautical etymologists believe that it may have derived elsewhere.
The earliest usage is found in a publication called Seaman’s Grammar from 1627: “A Bitter is but the turne of a Cable about the Bits, and veare it out by little and little. And the Bitters end is that part of the Cable doth stay within boord.”
So the bitt is a post fastened in the deck of a ship, for fastening cables and ropes. When a rope is played out to the bitter end, it means there is no more rope to be used.
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