welcome mat

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A mat, especially one having the word welcome on it, placed in front of a door to welcome visitors and to allow visitors a place to wipe their feet before entering.
• noun Warm hospitality accorded to a guest in order to provide a comfortable, welcoming atmosphere.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A doormat with a welcoming message on it.
• noun by analogy Any sign or indication of welcome.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a mat placed outside an exterior door for wiping the shoes before entering