a dwelling or building whose conventional appearance makes it a safe or inconspicuous place for hiding, taking refuge, or carrying on clandestine activities.
From POTUS To FLOTUS: A Full (White) House Of AcronymsThe faster we move, the more abbreviations and assorted acronyms we use, and when it comes to talking about the folks who reside at 1600 Pennsylvania Avenue—otherwise known as the White House—there are plenty of acronyms to choose from.
Origin of safe house
First recorded in 1960–65
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for safe house
a place used secretly by undercover agents, terrorists, etc, as a meeting place or refuge
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