know-all vs know-it-all

know-all and know-it-all both are nouns.

Word	Noun	Adjective	Verb	Adverb
know-all	Yes	No	No	No
know-it-all	Yes	No	No	No

As nouns, know-all and know-it-all are synonyms defined as:

know-all and know-it-all: someone who thinks he knows everything and refuses to accept advice or information from others

know-all (noun)	know-it-all (noun)
someone who thinks he knows everything and refuses to accept advice or information from others	someone who thinks he knows everything and refuses to accept advice or information from others