'contemporariness' originates from English, specifically formed from the adjective 'contemporary' plus the noun-forming suffix '-ness'; 'contemporary' itself comes from Late Latin 'contemporarius', where 'con-' meant 'together' and Latin 'tempus' meant 'time'.

'contemporariness' developed in modern English by adding '-ness' to 'contemporary' (from Middle English/early modern English 'contemporary', which was borrowed from Late Latin 'contemporarius'); over time the adjective produced several noun forms such as 'contemporaneity' and later the descriptive noun with '-ness'.

Initially the root meant 'together in time' (being of the same time), and over time the sense broadened to also include 'belonging to the present time' or 'modernity', which is the common contemporary sense.