failing

To be unsuccessful.

“Throughout my life, I have always failed.”

Not to achieve a particular stated goal. (Usage note: The direct object of this word is usually an infinitive.)

“The truck failed to start.”

To neglect.

“The report fails to take into account all the mitigating factors.”

Of a machine, etc.: to cease to operate correctly.

“After running five minutes, the engine failed.”

To be wanting to, to be insufficient for, to disappoint, to desert.

To receive one or more non-passing grades in academic pursuits.

“I failed English last year.”

To give a student a non-passing grade in an academic endeavour.

“The professor failed me because I did not complete any of the course assignments.”

To miss attaining; to lose.

To be wanting; to fall short; to be or become deficient in any measure or degree up to total absence.

“The crops failed last year.”

To be affected with want; to come short; to lack; to be deficient or unprovided; used with of.

To fall away; to become diminished; to decline; to decay; to sink.

To deteriorate in respect to vigour, activity, resources, etc.; to become weaker.

“A sick man fails.”

To perish; to die; used of a person.

To err in judgment; to be mistaken.

To become unable to meet one's engagements; especially, to be unable to pay one's debts or discharge one's business obligation; to become bankrupt or insolvent.

Weakness; defect

“His worst failing is his temper.”

If the preferred or prior option is not possible

“A large proportion of the females employed in other firms are said to have signified their intention of going on strike, failing a settlement.”