smoking jacket

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

• noun A man's evening jacket, often made of a fine fabric, elaborately trimmed, and usually worn at home.

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

• noun A men's jacket designed to be worn while smoking tobacco, typically made of soft fabric with a tie belt

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

• noun a man's soft jacket usually with a tie belt; worn at home