'deplasticizer' originates from English, specifically formed by the prefix 'de-' and the word 'plasticizer', where 'de-' meant 'remove' or 'reverse' and 'plasticizer' referred to 'an agent that makes materials plastic (flexible)'.

'plastic' comes from Greek 'plastikos' meaning 'fit for molding', passed into Latin and then into English; the verb 'plasticize' arose in the 19th century meaning 'to make plastic/flexible', and 'plasticizer' became the noun for the agent; the compound 'deplasticizer' was coined later (20th century) in polymer and materials science as the opposing agent.

Initially formed to mean 'an agent that reduces plasticity or removes plasticizer', the term has come to be used specifically for additives or treatments intended to neutralize or extract plasticizers or otherwise counteract plasticizing effects in formulations and processing.