'purposefully-kept' originates from the combination of 'purposefully' and 'kept', where 'purposefully' is derived from 'purpose' meaning 'intention' and '-fully' indicating 'in a manner of'.

'purposefully' evolved from the Middle English 'purpos', and 'kept' from the Old English 'cepan', eventually forming the modern English compound adjective 'purposefully-kept'.

Initially, 'purposefully' meant 'with intention', and 'kept' meant 'maintained'. Together, they evolved to mean 'maintained with intention'.