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.