'amidogen' originates from 'ammonia', specifically the word 'ammonium', where 'ammon-' referred to the chemical compound and '-ium' indicated a radical or ion.

'amidogen' changed from the earlier term 'ammonium radical' and eventually became the modern English word 'amidogen'.

Initially, it meant 'a radical derived from ammonia', and this meaning has largely remained the same in modern usage.