'tautness' originates from the Middle English word 'taught,' which is derived from the Old Norse word 'thattr,' meaning 'tight or drawn.'

'taught' transformed into the modern English word 'taut,' and eventually became 'tautness' to describe the state of being taut.

Initially, it meant 'tight or drawn,' but over time it evolved into its current meaning of 'the state of being stretched tight.'