'collectively-kept' originates from the combination of 'collectively' and 'kept', where 'collectively' is derived from 'collective', meaning 'done by people acting as a group', and 'kept' is the past participle of 'keep', meaning 'to maintain or preserve'.

'collectively-kept' evolved from the concept of 'collective' actions and 'keeping' something in a state of preservation, eventually forming the modern English term 'collectively-kept'.

Initially, it meant 'maintained by a group', and this meaning has largely remained the same in modern usage.