'privately-built' originates from the combination of 'private' and 'built', where 'private' comes from Latin 'privatus', meaning 'not public', and 'built' is the past participle of 'build', from Old English 'byldan'.

'Privatus' transformed into the Old French 'privé', and eventually became the modern English word 'private'. 'Byldan' evolved into the modern English 'build'.

Initially, 'private' meant 'not public', and 'built' meant 'constructed'. The combined term 'privately-built' retains the meaning of being constructed by non-governmental entities.