English idioms relating to mistakes-errors.

Idiom	Meaning
Go up a blind alley	If you go up a blind alley, you follow a course of action which first seemed promising but leads in the wrong direction or nowhere. "The revelations promised by the suspect lead the police up a blind alley."
Eat crow/eat humble pie	If you eat crow (or humble pie), you have to admit that you were wrong about something and apologize. "He had no option but to eat crow and admit that his analysis was wrong.
Eat one's words	If you eat your words, you have to admit that what you said before was wrong. "After predicting disastrous results, he had to eat his words with the success of the new product.
Freudian slip	This refers to a mistake made by a speaker which is considered to reveal their true thoughts or feelings. "So you got the job - I'm so sad - sorry, I mean glad!"
Himalayan blunder	If you stupidly make a very serious mistake or error, you commit a Himalayan blunder. "Apparently he lost his job because of a Himalayan blunder."
See the error of your ways	When someone sees the error of their ways, they understand that what they are doing is wrong and accept to change their behaviour. "He talked to a counsellor who tried to make him see the error of his ways."
Swallow one's pride	If you swallow your pride, you accept something humiliating or embarrassing, for example having to admit that you are wrong, or that you have less knowledge than you thought. "When Jill failed the exam, she had to swallow her pride and repeat the course."
Swallow one's words	If you swallow your words, you admit that you said something wrong. "He said I'd never get the job, but he had to swallow his words when I was appointed."
Trial and error	Attempting to achieve a satisfactory result by testing and eliminating various methods until the best one is found is called trial and error. "Some of the best cooks learn by trial and error."
Back the wrong horse	If you back or bet on the wrong horse, for example the loser in a contest, match or election, you support the wrong person. "When I voted for him, I was convinced he would win, but I backed the wrong horse!"
Bark up the wrong tree	A person who is barking up the wrong tree is doing the wrong thing, because their beliefs or ideas are incorrect or mistaken. "The police are barking up the wrong tree if they think Johnny stole the car. He can't drive!"
Wide of the mark	If something is (or falls) wide of the mark, it is incorrect or inadequate, or it is not what is required or expected. "The price offered was wide of the mark - it was sold for ten times more!"