'emission' originates from Latin, specifically the word 'emissio,' where 'e-' meant 'out' and 'mittere' meant 'to send.' 'Intensive' comes from Latin 'intensivus,' meaning 'stretched or strained.'

'emissio' transformed into the French word 'émission,' and eventually became the modern English word 'emission.' 'Intensivus' evolved into the French 'intensif,' leading to the modern English 'intensive.'

Initially, 'emission' meant 'the act of sending out,' but over time it evolved to refer specifically to the release of substances, especially gases. 'Intensive' has largely retained its original meaning of 'concentrated or strong.'