tian (tyäN)n.1. A shallow, oval, earthenware casserole.2. The food baked in this dish, typically consisting of sliced vegetables au gratin.[French, from Provençal, from Old Provençal, earthenware dish without handles, from Greek t?ganon, variant of tag?non, frying pan, saucepan; see tagine.]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.tian (tjæn) nan earthenware cooking disha traditional French vegetable stew cooked in such a dishCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014