Ex·cel·len·cy (?k?s?-l?n-s?)n. pl. Ex·cel·len·cies Abbr. Exc. Used with His, Her, or Your as a title and form of address for certain high officials, such as viceroys, ambassadors, and governors.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.Excellency (??ks?l?ns?) or Excellencen, pl -lencies or -lences1. (usually preceded by: Your, His, or Her) a title used to address or refer to a high-ranking official, such as an ambassador or governor2. (Roman Catholic Church) RC Church a title of bishops and archbishops in many non-English-speaking countriesCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014Ex?cel?len?cy (??k s? l?n si) n., pl. -cies. 1. Also, Excellence. a title of honor given to certain high officials, as governors, ambassadors, and Roman Catholic bishops and archbishops (prec. by His, Her, or Your). 2. a person so entitled. 3. (l.c.) Usu., excellencies. excellent qualities or features. [1275?1325; Middle English