-niksuff. One associated with or characterized by: beatnik; peacenik.[Yiddish and Russian (Yiddish, from Russian), of Slavic origin.]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.-nik suffix forming nouns denoting a person associated with a specified state, belief, or quality: beatnik; refusenik. [C20: from Russian -nik, as in Sputnik, and influenced by Yiddish -nik (agent suffix)]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014-nik a suffix of nouns that refer, often in a derogatory way, to persons who espouse a cause, represent a cultural attitude, or are ardent enthusiasts of a thing or phenomenon: beatnik; computernik; filmnik; peacenik. [