'antimoniuretted' is formed from 'antimony' + the chemical-forming element '-ure' (as in some compound names) plus the past-participle/adjectival suffix '-ed', used to indicate having been combined with or treated by antimony.

The element name 'antimony' (from Medieval Latin 'antimonium', Old French 'antimoine') was used to form compound nouns like 'antimoniure' in 18–19th century chemical literature; these yielded adjectival past-participles such as 'antimoniuretted' in technical descriptions.

Originally coined to describe materials 'made into or combined as an antimony compound' in older chemical practice; the meaning has remained specialized and largely historical/obsolete in modern terminology.