Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for apb
Find the area of triangle APB in terms of x, the side of the square.The Canterbury Puzzles|Henry Ernest Dudeney
abbreviation for (in the US)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
also a.p.b., 1960, police jargon initialism for all-points bulletin, itself attested by 1953 (perhaps more in the jargon of detective novels than in actual police use).
Online Etymology Dictionary, © 2010 Douglas Harper