As a girl's name this is a pet form of Jacqueline, as in the case of Jackie Kennedy Onassis (1929–94). It was originally a boy's name, a pet form of Jack. The racing driver Jackie Stewart (b. 1939) was originally named John Young Stewart.
English and French: 1. from the personal name Florence, used by both sexes (Latin Florentius (masculine) and Florentia (feminine), ultimately from flos, genitive floris ‘flower’). Both names were borne by several early Christian martyrs, but in the Middle Ages the masculine name was far more common. 2. local name for someone from Florence in Italy, originally named in Latin as Florentia.