standing room only.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for sro
It was SRO in the meeting room, packed to the gills with the entire ad-hoc, except for my new recruits.Down and Out in the Magic Kingdom|Cory Doctorow
British Dictionary definitions for sro
standing room only
British Statutory Rules and Orders
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
Word Origin and History for sro
1941, initialism for standing room only.
Online Etymology Dictionary, © 2010 Douglas Harper