'theoreticalness' originates from the word 'theoretical,' which is derived from the Greek word 'theōrētikos,' where 'theōrētikos' meant 'contemplative or speculative.'

'theōrētikos' transformed into the Latin word 'theoreticus,' and eventually became the modern English word 'theoretical' through Middle English.

Initially, it meant 'pertaining to contemplation or speculation,' but over time it evolved into its current meaning of 'pertaining to theory or abstract reasoning.'