Idiosyncrasy
Part of speech: noun
Definition: A behavior or way of thinking that is characteristic of a person. A language or behaviour that is particular to an individual or group. A peculiar individual reaction to a generally innocuous substance or factor. A peculiarity that serves to distinguish or identify.
Foible
Part of speech: adjective
Definition: weak.
Part of speech: noun
Definition: A quirk, idiosyncrasy, or mannerism; unusual habit or way (usage is typically plural), that is slightly strange or silly.A weakness or failing of character.Part of a sword between the middle and the point, weaker than the forte.