par·a-a·mi·no·ben·zo·ic acid (p?r??-?-m??n?-b?n-z???k, -?m??-)n. See PABA.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.para-aminobenzoic acid n (Biochemistry) biochem an acid present in yeast and liver: used in the manufacture of dyes and pharmaceuticals. Formula: C6H4(NH2)COOH Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014par?a-a?mi?no?ben?zo?ic ac?id (?pær ? ??mi no? b?n?zo? ?k, -?æm ? no?-) n. a yellowish, crystalline solid, C7H7NO2, that is a component of the vitamin B complex. Abbr.: PABA [1905?10] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.