Dictionary.com
definitions

Napoleon III

noun
  1. Louis NapoleonCharles Louis Napoleon Bonaparte, [loo-ee; French lwee] /ˈlu i; French lwi/1808–73, president of France 1848–52, emperor of France 1852–70 (nephew of Napoleon I).
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for napoleon iii

Napoleon III

noun
  1. full name Charles Louis Napoleon Bonaparte, known as Louis-Napoleon. 1808–73, Emperor of the French (1852–70); nephew of Napoleon I. He led two abortive Bonapartist risings (1836; 1840) and was elected president of the Second Republic (1848), establishing the Second Empire in 1852. Originally successful in foreign affairs, he was deposed after the disastrous Franco-Prussian War
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