chief·tain (ch?f?t?n)n. The leader or head of a group, especially of a clan or tribe.[Middle English cheftain, from Old French chevetain, from Late Latin capit?neus, from Latin caput, head; see kaput- in Indo-European roots.]chief?tain·cy n.chief?tain·ship? n.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.chieftain (?t?i?ft?n; -t?n) n1. (Anthropology & Ethnology) the head or leader of a tribe or clan2. the chief of a group of people[C14: from Old French chevetaine, from Late Latin capit?neus commander; see captain] ?chieftaincy, ?chieftain?ship nCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014chief?tain (?t?if t?n) n. 1. the chief of a clan or a tribe. 2. a leader of a group, band, etc.: the robbers’ chieftain. [1275?1325; Middle English cheftayne, variant of chevetaine