false friend

noun

a word or expression in one language that, because it resembles one in another language, is often wrongly taken to have the same meaning, for example, the French agenda which means diary, not agenda

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012