'reduced-starch' originates from Modern English as a compound of 'reduced' and 'starch'. 'reduced' is the past participle of 'reduce', which ultimately comes from Latin 'reducere', where 're-' meant 'back' and 'ducere' meant 'to lead'. 'starch' comes from Old English 'stearc', meaning 'stiff' or 'strong'.

'reduce' passed into English via Old French 'reduire' (from Latin 'reducere') and became Modern English 'reduce' with past participle 'reduced'. 'starch' evolved from Old English 'stearc' to Middle English forms such as 'sterche' and later modern English 'starch'. The compound 'reduced-starch' is a modern formation combining these elements.

Initially, 'reducere' conveyed the idea of 'leading back' and 'stearc' referred to 'stiffness'; over time 'reduce' developed the sense 'make smaller' and 'starch' came to denote the carbohydrate substance, so the compound now means 'having starch content reduced'.