'antiquitarian' originates from Latin, specifically the word 'antiquarius' (from 'antiquus'), where 'antiquus' meant 'ancient' or 'old'.

'antiquarius' in Latin developed into Medieval Latin forms and influenced the formation of English words such as 'antiquarian'; English 'antiquarian' and related formations led to the adjectival and nominal form 'antiquitarian' in later English usage.

Initially, the root signified simply 'of or belonging to ancient times/ancient things'; over time English uses preserved the sense 'relating to antiquities' and also acquired figurative senses like 'old-fashioned' or 'conservative'.