am·i·trip·tyl·ine (?m??-tr?p?t?-l?n?)n. A tricyclic antidepressant drug, C20H23N, used in the form of its hydrochloride salt.[Perhaps ami(no)- + alteration of trypt(ophan) + -yl + -ine.]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.amitriptyline (?æm??tr?pt??li?n; -l?n) n (Pharmacology) a tricyclic antidepressant drug. Formula: C20H23N[C20: from amino + tryptamine + methyl + -ine2]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014am?i?trip?ty?line (?æm ??tr?p t??lin, -?la?n, -l?n) n. a white crystalline powder, C20H23N, used to treat depression and enuresis. [1960?65; ami(no)- + tri- + (he)ptyl (see heptane, -yl) + -ine1] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.