'unburden' originates from Middle English, specifically the prefix 'un-' meaning 'not' or 'opposite of' and the word 'burden,' which meant 'a load or weight.'

'unburden' changed from the Middle English word 'unburdenen' and eventually became the modern English word 'unburden'.

Initially, it meant 'to remove a load or weight,' but over time it evolved into its current meaning of 'to relieve someone of a burden or worry.'