Usually small arms. a firearm designed to be held in one or both hands while being fired: in the U.S. the term is applied to weapons of a caliber of up to one inch (2.5 cm).
Origin of small arm
First recorded in 1680–90
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
portable firearms of relatively small calibre
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