Dictionary.com
definitions

box cutter

noun
  1. a small cutting tool consisting of a retractable razor blade in a metal or plastic holder, designed for opening cardboard cartons.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for box cutter

box cutter

noun
  1. a knife-like tool with a short retractable blade
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