'guiltlessly' originates from the Old English word 'gylt,' meaning 'crime or sin,' combined with the suffix '-less,' indicating 'without,' and '-ly,' forming an adverb.

'guiltless' evolved from the Old English 'gyltlēas,' meaning 'without guilt,' and eventually became the modern English word 'guiltless.'

Initially, it meant 'without guilt or sin,' and this meaning has largely remained the same in modern usage.