'reduced-impact' is a modern English compound formed by combining 'reduced' (the past participle of the verb 'reduce') and the noun 'impact'. 'Reduce' ultimately comes from Latin 'reducere' (re- 'back, again' + ducere 'to lead'), and 'impact' comes from Latin 'impactus' via French 'impact'.

'reduced' developed as the past participle form of Middle English/Old French verbs descended from Latin 'reducere'; 'impact' entered English from French in the 17th–18th centuries from Latin 'impactus' meaning 'a striking or pressing'. The compound adjective 'reduced-impact' is a descriptive formation from modern English usage (20th–21st century), used especially in environmental and design contexts.

Originally, Latin roots conveyed senses of 'leading back' ('reducere') and 'striking/pressing' ('impactus'); over time 'reduce' shifted to the common sense 'make smaller' or 'decrease', and 'impact' broadened to 'effect' or 'influence'. The compound now specifically means 'having a decreased effect', often in environmental contexts.