'azotous' originates from French, specifically the word 'azote', where the prefix 'a-' meant 'not' and Greek 'zōē' meant 'life' (so 'azote' = 'no life', an older name for nitrogen).

'azotous' was formed in modern English by combining French 'azote' (or scientific Latin/Neo-Latin forms such as 'azotum') with the English adjectival suffix '-ous', producing 'azotous' in chemical usage.

Initially, the root referred to the gas nitrogen (literally 'no life'); over time compounds named from that root came to be described as 'azotous' to mean 'relating to nitrogen' (a meaning that has largely remained, though usage is now rare and somewhat archaic).