'ricin-neutralizing' originates from modern English as a compound of 'ricin' and 'neutralizing'; 'ricin' ultimately comes from Latin 'ricinus' (via French) meaning 'castor oil plant', and 'neutralize' comes from French 'neutraliser' where 'neutral-' meant 'neuter, neither' and the suffix '-ize' meant 'to make or render'.

'ricin' entered English from French (from Latin 'ricinus'), while 'neutralize' was formed in English from French 'neutraliser' and the verb-forming suffix '-ize'; the compound 'ricin-neutralizing' is a recent technical formation combining the toxin name with the verb/adjective form.

Individually the parts kept their historical senses ('ricin' = the toxin, 'neutralize' = render ineffective); together the compound came to mean 'able to render ricin ineffective' in modern scientific usage.