'unlawfully-possessed' originates from the combination of 'unlawfully' and 'possessed', where 'unlawfully' means 'not conforming to the law' and 'possessed' means 'owned or held'.

'Possess' changed from the Old French word 'possesser' and eventually became the modern English word 'possess'.

Initially, 'possess' meant 'to hold or occupy', but over time it evolved to include the notion of ownership.