'depopularization' originates from Latin-derived elements and modern English word-formation: the prefix 'de-' (Latin) meaning 'down, away, or reverse', 'popular' from Latin 'popularis' (from 'populus' meaning 'people'), the verb-forming suffix '-ize' (via Greek/Latin -izein), and the noun-forming suffix '-ation'.

'depopularization' developed from the verb 'depopularize' (formed in modern English by adding 'de-' to 'popularize') and then the noun-forming suffix '-ation' was added to create 'depopularization'. 'popularize' itself entered English via French from Latin 'popularis'.

Originally, Latin 'popularis' meant 'of the people'; over time 'popular' shifted to mean 'well-liked by many', and 'de-' plus that root produced the modern sense 'to make less liked by many', hence 'depopularization' = 'making less popular'.