no·men·cla·ture (n??m?n-kl??ch?r, n?-m?n?kl?-)n.1. A system of names used in an art or science: the nomenclature of mineralogy.2. The system or procedure of assigning names to groups of organisms as part of a taxonomic classification: the rules of nomenclature in botany.[Latin n?mencl?t?ra, from n?mencl?tor, nomenclator; see nomenclator.]no?men·cla?tur·al adj.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.