'unheeded' originates from the prefix 'un-' meaning 'not' and the word 'heed' from Old English 'hēdan', meaning 'to observe or give attention to'.

'heed' changed from the Old English word 'hēdan' and eventually became the modern English word 'heed'.

Initially, it meant 'to observe or give attention to', but over time, 'unheeded' evolved to mean 'not noticed or given attention to'.