'eagerly-returned' is a compound word formed from 'eagerly' and 'returned'. 'Eagerly' originates from Middle English 'eager', from Old French 'eagre', from Latin 'acer', meaning 'sharp, keen'. 'Returned' is the past participle of 'return', from Old French 'retourner', from Latin 're-' meaning 'back' and 'tornare' meaning 'to turn'.

'Eagerly' evolved from the Latin 'acer' through Old French 'eagre', while 'returned' evolved from Latin 'retornare' through Old French 'retourner'.

Initially, 'eagerly' meant 'keen or sharp', and 'returned' meant 'to turn back'. Over time, 'eagerly-returned' came to mean returning with enthusiasm.