A quirky trait is a personality characteristic that is unusual or unexpected. It is often seen as an endearing quality, but can also be perceived as strange or off-putting. The term 'TIC' is an acronym for Tourette's Syndrome, which is a neurological disorder characterized by involuntary physical and vocal tics. People with Tourette's Syndrome often have quirky traits, such as making sudden movements or noises, that are associated with the disorder.