Definition of "Caro"

She hadn't realized that 'Caro' was a diminutive of Caroline until she met Jonathan. It sounded very Regency, like in all those historical novels she used to read when she was younger. Much younger. Of course, he came from the kind of background - county - where people are called 'Caroline'. And Lucy and Amanda and Jemima, so he should know.

2004, Kate Atkinson, Case Histories, pages 96–97