default on vs default

default on is not a noun while default is a noun.

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

As verbs, default on and default are synonyms defined as:

default on (noun)	default (noun)
	loss due to not showing up
	an option that is selected automatically unless an alternative is specified
	loss resulting from failure of a debt to be paid
	act of failing to meet a financial obligation

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