'silicate-free' is a modern English compound formed from 'silicate' + 'free'. 'Silicate' comes from New Latin 'silicatus' (from 'silica'), where 'silica' derives from Latin 'silex, silicis' meaning 'flint' or 'hard stone', and the chemical suffix '-ate' (from Latin/Greek) denotes salts or esters. 'Free' comes from Old English 'frēo' meaning 'not subject to, exempt'.

'silicate' developed in scientific New Latin/modern chemistry from Latin 'silica' and Medieval/New Latin forms such as 'silicatus', and entered English as the chemical noun 'silicate'. 'Free' evolved from Old English 'frēo' through Middle English to modern 'free'. The compound 'silicate-free' is a relatively recent coinage in product/technical descriptions formed by joining the noun and adjective.

Originally, 'silicate' referred to salts or esters of silicic acid (chemical sense), and 'free' originally meant 'not bound or subject to'. The compound's meaning has straightforwardly become 'not containing silicates' in modern usage, especially on ingredient labels and technical descriptions.