default on vs fail

default on and fail both are verbs.

Word	Noun	Adjective	Verb	Adverb
default on	No	No	Yes	No
fail	No	No	Yes	No

As verbs, fail is a hypernym of default on; that is, fail is a word with a broader meaning than default on:

Other hypernyms of default on include neglect.

default on (verb)	fail (verb)
fail to pay up	stop operating or functioning
	deteriorate
	prove insufficient
	disappoint, prove undependable to; abandon, forsake
	become bankrupt or insolvent; fail financially and close
	be unsuccessful
	fail to get a passing grade
	fail to do something; leave something undone
	judge unacceptable
	be unable
	fall short in what is expected