Who came up with the definition of synchronicity?

Synchronicity (German: Synchronizität) is a concept first introduced by analytical psychologist Carl G. Jung "to describe circumstances that appear meaningfully related yet lack a causal connection." In contemporary research, synchronicity experiences refer to a person's subjective experience that coincidences between events in their mind and the outside world may be causally unrelated to each other yet have some other unknown connection. Jung held that this was a healthy, even necessary, function of the human mind that can become harmful within psychosis.