an·i·line also an·i·lin (?n??-l?n)n. A colorless, oily, poisonous benzene derivative, C6H7N, used in the manufacture of rubber, dyes, resins, pharmaceuticals, and varnishes.adj. Derived from aniline.[anil + -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.aniline (?æn?l?n; -?li?n) or anilinn (Elements & Compounds) a colourless oily pungent poisonous liquid used in the manufacture of dyes, plastics, pharmaceuticals, and explosives. Formula: C6H5NH2. Also called: phenylamine Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014an?i?line (?æn l ?n, -?a?n) also an?i?lin (-?n) n. a colorless, oily, slightly water-soluble liquid, C6H5NH2, used chiefly in the synthesis of dyes and drugs. [1840?50; anil + -ine2] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.