'starch-thickened' originates from modern English, specifically the compound of 'starch' and 'thicken', where 'starch' ultimately comes from Old English 'stearc' (from Proto-Germanic *starkaz) meaning 'stiff', and 'thicken' is formed from Old English 'þicce' ('thick') with the verbal suffix '-en'.

'starch' changed from Old English 'stearc' to Middle English forms such as 'sterch'/'sterche' and eventually became the modern English 'starch'; 'thicken' developed in Middle English from the adjective 'thick' + suffix '-en' to form the verb and its past participle 'thickened'. The compound 'starch-thickened' is a later modern English combining form describing something made thicker by starch.

Initially, 'starch' primarily referred to a substance that made textiles or foods stiff; over time the compound sense evolved into the more specific modern meaning 'made thicker with starch'.