Arthur Wellesley art·hur·wel·lesley uncommon noun 1. British general and statesman; he defeated Napoleon at Waterloo; subsequently served as Prime Minister (1769-1852) SynonymsWellingtonDuke of WellingtonFirst Duke of WellingtonArthur Wellesleythe Iron Duke Related words Broader terms generalstatesman WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.