Word Study
prussic
CIDE DICTIONARY
prussic, a. [Cf. F. prussique.].
designating the acid now called hydrocyanic acid, but formerly called prussic acid, because Prussian blue is derived from it or its compounds. See Hydrocyanic. [1913 Webster]
OXFORD DICTIONARY
prussic, adj. of or obtained from Prussian blue.
Idiom
prussic acid hydrocyanic acid.
Etymology
F prussique f. Prusse Prussia
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