'unsowable' originates from the prefix 'un-' meaning 'not' and the word 'sow' from Old English 'sāwan', meaning 'to plant seeds'.

'sāwan' transformed into the Middle English word 'sowen', and eventually became the modern English word 'sow'.

Initially, it meant 'to plant seeds', and over time, the prefix 'un-' was added to denote the opposite, 'not suitable for planting'.