knee breeches

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

• noun plural Trousers extending to or just below the knee.

from The Century Dictionary.

• Breeches that reach to the knee or just below it; especially, a close-fitting garment covering the thigh and the lower part of the body, worn generally from the beginning of the eighteenth century until about 1815. See knickerbocker, 3.

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

• noun trousers ending above the knee