The term 'slowly-changed' is a compound adjective formed from 'slowly' and 'changed'. 'Slowly' originates from Old English 'slāwlice', meaning 'in a slow manner', and 'changed' comes from Old French 'changier', meaning 'to alter'.

'Slowly' evolved from Old English 'slāwlice', while 'changed' evolved from Old French 'changier'. The combination of these words into 'slowly-changed' is a modern English construct.

Initially, 'slowly' meant 'in a slow manner', and 'changed' meant 'to alter'. The combination retains the original meanings, describing a gradual transformation.