'prosaicize' originates from English, specifically the word 'prosaic' combined with the suffix '-ize' (from Greek via Latin/French), where '-ize' meant 'to make' or 'to cause to be'.

'prosaic' comes from Latin, specifically the word 'prosaicus' (from 'prosa' meaning 'prose'), and this combined form plus the productive verbal suffix '-ize' yielded 'prosaicize' in English; the past form became 'prosaicized'.

Initially related to 'prose' or 'being like prose' (straightforward, non-poetic), it evolved into the verbal sense 'to make something ordinary or dull', which is the current sense of 'prosaicize' and thus 'prosaicized'.