'smoothly-progressed' originates from the combination of 'smoothly' and 'progressed', where 'smoothly' is derived from 'smooth', meaning 'even or without roughness', and 'progressed' is the past tense of 'progress', meaning 'to move forward'.

'smoothly' evolved from the Old English word 'smōð', and 'progressed' from the Latin word 'progressus', meaning 'a going forward'.

Initially, 'smoothly' meant 'without roughness', and 'progressed' meant 'to advance'. Together, they convey the idea of advancing without obstacles.