'mystically' originates from the Greek word 'mystikos,' where 'mystikos' meant 'secret' or 'mystical.'

'mystikos' transformed into the Latin word 'mysticus,' and eventually became the modern English word 'mystical,' from which 'mystically' is derived.

Initially, it meant 'pertaining to mysteries or secret rites,' but over time it evolved into its current meaning of 'in a mysterious or spiritual manner.'