thou(redirected from Archaic second person singular)
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1. one thousandth of an inch. 1 thou is equal to 0.0254 millimetre
2. Informal short for thousand
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.