foible vs idiosyncrasy

foible and idiosyncrasy both are nouns.

Word	Noun	Adjective	Verb	Adverb
foible	Yes	No	No	No
idiosyncrasy	Yes	No	No	No

As nouns, foible and idiosyncrasy are synonyms defined as:

foible and idiosyncrasy: a behavioral attribute that is distinctive and peculiar to an individual

Other synonyms of foible include mannerism.

foible (noun)	idiosyncrasy (noun)
the weaker part of a sword's blade from the forte to the tip	a behavioral attribute that is distinctive and peculiar to an individual
a behavioral attribute that is distinctive and peculiar to an individual
a minor flaw or shortcoming in character or behavior.