'exactly-defined' originates from the combination of 'exactly' and 'defined', where 'exactly' comes from Latin 'exactus', meaning 'precisely', and 'defined' comes from Latin 'definire', meaning 'to limit or determine'.

'exactly' changed from the Latin word 'exactus' and 'defined' from 'definire', eventually forming the modern English term 'exactly-defined'.

Initially, 'exactly' meant 'precisely' and 'defined' meant 'to limit or determine', and together they evolved to mean 'clearly and precisely specified'.