'depolymerization' originates from Modern English, specifically from the prefix 'de-' and the word 'polymerization', where 'de-' meant 'reverse' or 'remove' and 'polymer' (from Greek) meant 'many parts'.

'polymer' comes from Greek elements 'polus' ('many') + 'meros' ('part'); 'polymerization' was formed in the 19th century by adding the suffix '-ization' to 'polymer'; the scientific formation 'depolymerization' arose by adding the prefix 'de-' to indicate reversal of that process in later 19th–20th century technical usage.

Initially the components 'polymer' and 'polymerization' referred to 'many parts' and the formation of large molecules; 'depolymerization' developed to mean specifically the reversal—breaking those large molecules back into smaller units—and has retained that technical sense.