idiosyncrasy
noun /ˌɪdiəˈsɪŋkrəsi/
  /ˌɪdiəˈsɪŋkrəsi/
[countable, uncountable] (plural idiosyncrasies)
- a person’s particular way of behaving, thinking, etc., especially when it is unusual; an unusual feature synonym eccentricity
- Wearing a raincoat, even on a hot day, is one of her idiosyncrasies.
 - The car has its little idiosyncrasies.
 
Extra Examples- The microphone is likely to exaggerate the idiosyncrasies of a voice.
 - We are all individuals, unique beings with our own special qualities and idiosyncrasies.
 
Word Originearly 17th cent. (originally in the sense ‘physical constitution peculiar to an individual’): from Greek idiosunkrasia, from idios ‘own, private’ + sun ‘with’ + krasis ‘mixture’.