'neologism' originates from Modern Latin, specifically the word 'neologismus', which ultimately comes from Greek elements 'neo-' and 'logos' where 'neo-' meant 'new' and 'logos' meant 'word/speech'.

'neologism' came into English via Modern Latin 'neologismus' and French influences from Greek 'neologismos' (νεολογισμός), eventually becoming the English word 'neologism'.

Initially it referred specifically to a 'new word' (from the Greek), but over time it came to include newly coined expressions and new meanings of existing words as used in modern English.