'substantially' originates from Latin, specifically the word 'substantialis,' where 'substantia' meant 'essence or substance.' 'Altered' comes from Latin 'alterare,' meaning 'to change.'

'substantialis' transformed into the Old French word 'substantiel,' and eventually became the modern English word 'substantial.' 'Alterare' evolved into the Old French 'alterer,' leading to the modern English 'alter.'

Initially, 'substantially' meant 'in essence or substance,' but over time it evolved to mean 'to a great extent.' 'Altered' has maintained its meaning of 'changed.'