sore loser who stubbornly refuses to admit being wrong
A yojijukugo describing someone who, when proven wrong, twists logic to insist they are right. Rare and literary; often used to characterize a stubborn, argumentative person.
See also: 漱石枕流
When he loses an argument, he takes the attitude of a sore loser who won't admit he's wrong.
Same meaning, but the character order is reversed. 枕流漱石 is the more common form.
Derived from a Chinese anecdote in which a man, after mistakenly saying he would use a rock as a pillow and rinse his mouth with a stream, stubbornly reinterpreted the words to avoid admitting his error. The phrase literally means 'pillow on a stream, rinse mouth with a rock.'