default vs failure

default and failure both are nouns.

Word	Noun	Adjective	Verb	Adverb
default	Yes	No	Yes	No
failure	Yes	No	No	No

As nouns, failure is a hypernym of default; that is, failure is a word with a broader meaning than default:

default (noun)	failure (noun)
loss due to not showing up	an act that fails
an option that is selected automatically unless an alternative is specified	an unexpected omission
loss resulting from failure of a debt to be paid	an event that does not accomplish its intended purpose
act of failing to meet a financial obligation	a person with a record of failing; someone who loses consistently
	lack of success
	loss of ability to function normally
	inability to discharge all your debts as they come due

default (verb)	failure (verb)
fail to pay up