1) Rodent pesticide 2) White arsenic 
• (n.) Rat poison; white arsenic.
Synonym for arsenic ... 1. <chemistry> One of the elements, a solid substance resembling a metal in its physical properties, but in its chemical relations ranking with the nonmetals. It is of a steel-gray colour and brilliant luster, though usually dull from tarnish. It is very brittle, and sublimes at 356 deg Fahrenheit. It is sometimes foun...
Rats'bane` (răts'bān`) noun [ Rat + bane .] Rat poison; white arsenic. 
Type: Term Pronunciation: rats′bān Synonyms: arsenic