Eccentricity retiene su noción fundamental de encontrarse uno fuera del centro, y en este uso recalca la divergencia de lo acostumbrado o usual <as she grew older, her eccentricity increased>.
Idiosyncrasy recalca una característica plenamente individual e independiente, y en muchas ocasiones connota seguidores de las extrañas inclinaciones o temperamento de uno <he regarded the habit as a harmless idiosyncrasy>.
Quirk sugiere un rasgo personal o un hábito que es inusual o raro <his quirks only made him more attractive to her>.
Mannerism indica un hábito de comportamiento pequeño pero distintivo <she had a mannerism of constantly adjusting her glasses>.
Peculiarity connota algo raro o anormal, no necesariamente un rasgo de conducta <the illness was caused by a peculiarity of his nervous system>.
