'zeolite-free' originates from English, specifically the combination of the word 'zeolite' and the word 'free', where 'zeolite' comes from Greek roots 'zeō' (to boil) + 'lithos' (stone) and 'free' ultimately comes from Old English 'frēo' meaning 'without / exempt'.

'zeolite' entered scientific vocabulary via New Latin/modern usage from Greek 'zeō' + 'lithos' (originally describing minerals that seemed to 'boil' when heated); later English formed the compound adjective 'zeolite-free' by combining the established mineral name 'zeolite' with the adjective 'free'.

Initially, 'zeolite' described a group of minerals that appeared to 'boil' when heated; over time the mineral name remained stable, and the modern compound 'zeolite-free' has come to mean 'lacking or not containing zeolite'.