fer de lance
Concise Oxford English Dictionary © 2008 Oxford University Press:
fer de lance /ˌfɛː də ˈlɑːns/
▶noun (pl. fers de lance pronunc. same or fer de lances) a large and dangerous pit viper native to Central and South America. [Bothrops atrox and related species.]
– origin C19: from Fr., lit. ‘iron (head) of a lance’.
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