'miasm' originates from Greek, specifically the word 'miasma', where the stem 'miainein' meant 'to pollute' or 'to stain'.

'miasm' developed via Late Latin and Medieval Latin 'miasma' (from Greek 'míasma') into English; the shorter form 'miasm' is a later English variant related to 'miasma'.

Initially it referred to 'pollution' or a 'stain' and, in medical contexts, to a noxious vapor believed to cause disease; over time it has broadened to include a figurative sense of a corrupting or oppressive atmosphere.