'non-tumorous' originates from the prefix 'non-' meaning 'not' and the word 'tumorous' which comes from Latin 'tumor' meaning 'swelling'.

'tumorous' changed from the Latin word 'tumor' and eventually became the modern English word 'tumorous'.

Initially, 'tumorous' meant 'swelling', but over time it evolved to mean 'relating to or affected by a tumor'. 'Non-tumorous' retains the original meaning of 'not involving a tumor'.