【Failure】 , 【neglect】 ,  【default】 ,  【miscarriage】 ,  【dereliction】  are comparable when they mean an omission on the part of someone or something of what is expected or required of him or of it.

【Failure】 basically implies a being found wanting; it implies a lack or absence of something that might have been expected to occur or to be accomplished, performed, or effected.

【Neglect】  (see also NEGLIGENCE ) implies carelessness and inattentiveness on the part of a person, so that what is expected or required of him is either left unattended to or is not adequately performed.

【Default】 is now chiefly found in legal use, where it implies a 【failure】 to perform something required by law (as a 【failure】 of a plaintiff or of a defendant to appear at the appointed time to prosecute or defend an action or a proceeding).

【Default】 may also imply a 【failure】 to pay one’s debts at the appointed time or in extended use a 【failure】 to perform something required, usually by total omission of pertinent action.

【Miscarriage】 does not so definitely point the blame for a 【failure】 of someone or something to live up to expectations or to accomplish certain ends as do the preceding words; it is often used when there are no definite persons or things to which culpability can be assigned or when for some reason or other there is a desire to avoid casting of blame.

【Dereliction】 , of all these terms, carries the strongest implication of a 【neglect】 that amounts to an abandonment of, or a departure from, the thing and especially the duty, the principle, or the law that should have been uppermost in a person’s mind; ordinarily it implies a morally reprehensible 【failure】 rather than one resulting from carelessness and inattention or from mishap.