'overreward' originates from the combination of 'over-' meaning 'excessive' and 'reward' meaning 'something given in return for service or merit'.

'overreward' evolved from the Old English word 'rewardian', which meant 'to give a reward', with the prefix 'over-' added to indicate excess.

Initially, it meant 'to give a reward', but over time it evolved into its current meaning of 'to give more reward than deserved'.