1 a : to not succeed : to end without success [no obj] ▪ He failed in his first attempt but succeeded in his second attempt. ▪ The rebellion failed completely. ▪ an experiment that failed = a failed experiment ▪ a marriage that is failing = a failing marriage ▪ The drought caused the crops to fail. [=the crops did not grow successfully because of the drought] ▪ He only bothers to read the directions if/when all else fails. [=if/when everything else he has attempted has failed] [+ obj] — followed by to + verb ▪ She failed to finish the race. ▪ He failed to achieve all that he hoped to achieve.
b [no obj] : to not succeed as a business : to become bankrupt
▪ His first company failed, but his second company succeeded. ▪ The bank failed. ▪ a failed bank 2 a [+ obj] : to not do (something that you should do or are expected to do) — followed by to + verb ▪ He failed to act on the advice of his staff. [=he should have acted on their advice but he didn't] ▪ He failed to mention his new girlfriend when he spoke to his parents.
b : to not do something [+ obj] — followed by to + verb ▪ I turned on the switch but the light failed to go on. ▪ It never fails to surprise me that people can be so gullible. [=I am always surprised that people can be so gullible] ▪ Her public appearances rarely fail to attract huge crowds. [=her public appearances almost always attract huge crowds] ▪ It never fails to rain [=it always rains] when I plan to take a day off. ▪ I fail to see/understand [=I don't see/understand] why we need to change the current system. [=I don't think we need to change it] [no obj] ▪ It never fails: I plan to take a day off, and it rains. [=whenever I plan to take a day off, it rains] 3 [+ obj] : to not do or provide something that is needed by (someone)
▪ He felt that he had failed her when she needed him most. ▪ The government has failed the voters. ▪ In the face of continued threats, his courage failed him. [=he lost courage, he became afraid] ▪ He wanted to express his appreciation for all they had done, but words failed him. [=he did not know what to say] 4 a : to be unsuccessful in passing (an examination, a course of study, etc.) [+ obj] ▪ He failed the test/exam. ▪ He failed chemistry. [no obj] ▪ He failed in chemistry. ▪ Failing students must repeat the course.
b [+ obj] : to decide that (someone) has not passed an examination or course of study
▪ The teacher failed several students. ▪ He received a failing grade/mark in chemistry. [=his teacher gave him a grade/mark that showed he failed chemistry] 5 [no obj] a : to stop working
▪ The power failed. ▪ The plane's engine failed, forcing an emergency landing. ▪ His kidneys failed.
b : to lose strength : to become weak or weaker
▪ Her health/eyesight is starting to fail. ▪ Her children are concerned about her failing health/eyesight.