Definition of "walk-in" []

• Large enough to admit entrance: a walk-in closet. (adjective)
• Located so as to be entered directly from the street: a walk-in apartment. (adjective)
• A room large enough to admit entrance. (noun)
• An easily won victory, especially in an election. (noun)
• Slang One who walks in without having an appointment. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The report helpfully cited the definition of walk-in in Spy Book: The Encyclopedia of Espionage, by Norman Polmar and Thomas B. Allen: “An unheralded defector or a dangle, a ‘walk-in’ is a potential agent or a mole who literally walks into an embassy or intelligence agency without prior contact or recruitment.”"
• "I resisted the temptation to use a phone kiosk and call the walk-in clinic to get the results of my HIV test – out of the fear that someone would report back to them that I was seen on the phone and, ergo, to the cops."
• "However, when a source, worried about confirming a leak, waves a reporter off a story that is true as Cox did with my early query about a walk-in, that is considered by the inquirer to be a misstep in the symbiosis minuet."