tea bag

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

• noun A small porous sack holding enough tea leaves to make an individual serving of tea.

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

• noun A small porous bag, holding tea leaves or the herbal equivalent; used to brew a single cup of tea.
• verb intransitive, slang To protest against those favoring increasing economic power of the US federal government (as part of the Tea Party).

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

• noun a measured amount of tea in a bag for an individual serving of tea
• noun small paper bag holding a measure of tea